diff --git a/src/shared/agent-session-option-agent-args.ts b/src/shared/agent-session-option-agent-args.ts
index d357ea57b73..eed4f1ec3ed 100644
--- a/src/shared/agent-session-option-agent-args.ts
+++ b/src/shared/agent-session-option-agent-args.ts
@@ -1,35 +1,24 @@
+import { findOptionOccurrence } from './command-option-occurrence'
+
 export function agentArgOptionTokens(tokens: readonly string[]): readonly string[] {
   const terminator = tokens.indexOf('--')
   return terminator === -1 ? tokens : tokens.slice(0, terminator)
 }
 
+/** Removes each occurrence before `--`, or only those whose value `matchesValue` accepts. */
 export function removeAgentArgOption(
   tokens: readonly string[],
-  aliases: readonly string[]
+  aliases: readonly string[],
+  matchesValue: (value: string | undefined) => boolean = () => true
 ): string[] {
-  const result: string[] = []
-  for (let index = 0; index < tokens.length; index += 1) {
-    const token = tokens[index]
-    if (token === '--') {
-      result.push(...tokens.slice(index))
-      break
-    }
-    const exact = aliases.includes(token)
-    const matched = aliases.some(
-      (alias) =>
-        token.startsWith(`${alias}=`) ||
-        (alias.startsWith('-') &&
-          !alias.startsWith('--') &&
-          token.startsWith(alias) &&
-          token.length > alias.length)
-    )
-    if (!exact && !matched) {
-      result.push(token)
-      continue
-    }
-    if (exact && tokens[index + 1] && !tokens[index + 1].startsWith('-')) {
-      index += 1
-    }
+  const kept: string[] = []
+  let rest = tokens
+  let found = findOptionOccurrence(rest, aliases, true)
+  while (found) {
+    const end = found.index + found.consumed
+    kept.push(...rest.slice(0, matchesValue(found.value) ? found.index : end))
+    rest = rest.slice(end)
+    found = findOptionOccurrence(rest, aliases, true)
   }
-  return result
+  return [...kept, ...rest]
 }
diff --git a/src/shared/agent-session-option-catalog-antigravity.ts b/src/shared/agent-session-option-catalog-antigravity.ts
index e6427a1070b..a2078c963d8 100644
--- a/src/shared/agent-session-option-catalog-antigravity.ts
+++ b/src/shared/agent-session-option-catalog-antigravity.ts
@@ -1,4 +1,3 @@
-import { hasFlag } from './agent-cli-flag-detection'
 import { removeAgentArgOption } from './agent-session-option-agent-args'
 import type { AgentSessionOptionCatalog, CatalogOption } from './agent-session-option-catalog-types'
 
@@ -17,7 +16,6 @@ const ANTIGRAVITY_EFFORT: CatalogOption = {
   },
   apply: {
     launchArgs: (value) => ['--effort', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--effort']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--effort']),
     midSession: { kind: 'command', build: (value) => `/effort ${String(value)}` }
   }
@@ -29,7 +27,6 @@ export const ANTIGRAVITY_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   models: [],
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--model']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--model']),
     midSession: { kind: 'agent-picker', command: '/model' }
   },
diff --git a/src/shared/agent-session-option-catalog-claude-codex.ts b/src/shared/agent-session-option-catalog-claude-codex.ts
index b7e9d0e6bed..9fb27d3a97f 100644
--- a/src/shared/agent-session-option-catalog-claude-codex.ts
+++ b/src/shared/agent-session-option-catalog-claude-codex.ts
@@ -3,55 +3,24 @@ import type {
   CatalogModel,
   CatalogOption
 } from './agent-session-option-catalog-types'
-import { agentArgOptionTokens, removeAgentArgOption } from './agent-session-option-agent-args'
+import { removeAgentArgOption } from './agent-session-option-agent-args'
 import {
   CLAUDE_MODEL_LIST_ARGS,
   CLAUDE_MODEL_LIST_STDIN,
   parseClaudeModelList
 } from './claude-model-list-probe'
-import { hasFlag } from './agent-cli-flag-detection'
 
-function hasCodexEffortOverride(tokens: readonly string[]): boolean {
-  if (hasFlag(tokens, ['--reasoning-effort'])) {
-    return true
-  }
-  const optionTokens = agentArgOptionTokens(tokens)
-  return optionTokens.some((token, index) => {
-    const previous = optionTokens[index - 1]
-    return (
-      (token.startsWith('model_reasoning_effort=') &&
-        (previous === '-c' || previous === '--config')) ||
-      token.startsWith('-cmodel_reasoning_effort=') ||
-      token.startsWith('-c=model_reasoning_effort=') ||
-      token.startsWith('--config=model_reasoning_effort=')
-    )
-  })
-}
-
-function removeCodexEffortOverride(tokens: readonly string[]): string[] {
-  const withoutFlag = removeAgentArgOption(tokens, ['--reasoning-effort'])
-  const result: string[] = []
-  for (let index = 0; index < withoutFlag.length; index += 1) {
-    const token = withoutFlag[index]
-    if (token === '--') {
-      result.push(...withoutFlag.slice(index))
-      break
-    }
-    const next = withoutFlag[index + 1]
-    if ((token === '-c' || token === '--config') && next?.startsWith('model_reasoning_effort=')) {
-      index += 1
-      continue
-    }
-    if (
-      token.startsWith('-cmodel_reasoning_effort=') ||
-      token.startsWith('-c=model_reasoning_effort=') ||
-      token.startsWith('--config=model_reasoning_effort=')
-    ) {
-      continue
-    }
-    result.push(token)
-  }
-  return result
+// Why: Codex also reads any setting from a `-c key=value` config override.
+function removeCodexAgentArgs(
+  tokens: readonly string[],
+  flags: readonly string[],
+  configKey: string
+): string[] {
+  return removeAgentArgOption(
+    removeAgentArgOption(tokens, flags),
+    ['-c', '--config'],
+    (value) => value?.startsWith(`${configKey}=`) === true
+  )
 }
 
 const STANDARD_EFFORT_CHOICES = [
@@ -84,7 +53,6 @@ function claudeEffortWithChoices(choices: typeof EXTENDED_EFFORT_CHOICES): Catal
     },
     apply: {
       launchArgs: (value) => ['--effort', String(value)],
-      agentArgsOverride: (tokens) => hasFlag(tokens, ['--effort']),
       removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--effort']),
       midSession: { kind: 'command', build: (value) => `/effort ${String(value)}` }
     }
@@ -162,7 +130,6 @@ export const CLAUDE_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ],
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--model']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--model']),
     midSession: {
       kind: 'command',
@@ -204,8 +171,8 @@ function codexEffort(ceiling: 'xhigh' | 'max' | 'ultra'): CatalogOption {
     },
     apply: {
       launchArgs: (value) => ['-c', `model_reasoning_effort=${String(value)}`],
-      agentArgsOverride: hasCodexEffortOverride,
-      removeAgentArgs: removeCodexEffortOverride,
+      removeAgentArgs: (tokens) =>
+        removeCodexAgentArgs(tokens, ['--reasoning-effort'], 'model_reasoning_effort'),
       midSession: { kind: 'agent-picker', command: '/model', delivery: 'type' }
     }
   }
@@ -228,8 +195,7 @@ export const CODEX_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ],
   modelApply: {
     launchArgs: (value) => ['-m', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['-m', '--model']),
-    removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['-m', '--model']),
+    removeAgentArgs: (tokens) => removeCodexAgentArgs(tokens, ['-m', '--model'], 'model'),
     // Codex classifies multi-character writes as pasted prose; type the bare
     // command and let its own picker apply the account-supported model.
     midSession: { kind: 'agent-picker', command: '/model', delivery: 'type' }
diff --git a/src/shared/agent-session-option-catalog-codebuddy.ts b/src/shared/agent-session-option-catalog-codebuddy.ts
index d0a8afa04c5..9c149919472 100644
--- a/src/shared/agent-session-option-catalog-codebuddy.ts
+++ b/src/shared/agent-session-option-catalog-codebuddy.ts
@@ -1,4 +1,3 @@
-import { hasFlag } from './agent-cli-flag-detection'
 import { removeAgentArgOption } from './agent-session-option-agent-args'
 import type { AgentSessionOptionCatalog, CatalogOption } from './agent-session-option-catalog-types'
 
@@ -20,7 +19,6 @@ const CODEBUDDY_EFFORT: CatalogOption = {
   },
   apply: {
     launchArgs: (value) => ['--effort', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--effort']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--effort'])
   }
 }
@@ -37,7 +35,6 @@ export const CODEBUDDY_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ].map((model) => ({ ...model, options: [CODEBUDDY_EFFORT] })),
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--model']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--model'])
   },
   unknownModelOptions: [CODEBUDDY_EFFORT]
diff --git a/src/shared/agent-session-option-catalog-gemini-cursor.ts b/src/shared/agent-session-option-catalog-gemini-cursor.ts
index d6dfe08627e..510394d2bd5 100644
--- a/src/shared/agent-session-option-catalog-gemini-cursor.ts
+++ b/src/shared/agent-session-option-catalog-gemini-cursor.ts
@@ -1,4 +1,3 @@
-import { hasFlag } from './agent-cli-flag-detection'
 import type {
   AgentSessionOptionCatalog,
   CatalogModel,
@@ -6,7 +5,8 @@ import type {
 } from './agent-session-option-catalog-types'
 import { removeAgentArgOption } from './agent-session-option-agent-args'
 
-const hasModelFlag = (tokens: readonly string[]): boolean => hasFlag(tokens, ['-m', '--model'])
+const removeModelFlag = (tokens: readonly string[]): string[] =>
+  removeAgentArgOption(tokens, ['-m', '--model'])
 
 export const GEMINI_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   models: [
@@ -17,7 +17,7 @@ export const GEMINI_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ],
   modelApply: {
     launchArgs: (value) => ['-m', String(value)],
-    agentArgsOverride: hasModelFlag,
+    removeAgentArgs: removeModelFlag,
     midSession: { kind: 'agent-picker', command: '/model' }
   }
 }
@@ -86,8 +86,7 @@ export const CURSOR_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ],
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: hasModelFlag,
-    removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['-m', '--model']),
+    removeAgentArgs: removeModelFlag,
     midSession: { kind: 'command', build: (value) => `/model ${String(value)}` }
   },
   composeModelValue: (modelId, values) => {
diff --git a/src/shared/agent-session-option-catalog-grok.test.ts b/src/shared/agent-session-option-catalog-grok.test.ts
index 0295cb46ad7..7a54621c7c6 100644
--- a/src/shared/agent-session-option-catalog-grok.test.ts
+++ b/src/shared/agent-session-option-catalog-grok.test.ts
@@ -179,32 +179,37 @@ describe('grok launch args', () => {
   })
 })
 
-describe('grok agentArgsOverride', () => {
-  const modelOverride = GROK_SESSION_OPTION_CATALOG.modelApply.agentArgsOverride!
-  const effortOverride = grokEffortOption().apply.agentArgsOverride!
+describe('grok agent-arg overrides', () => {
+  const removeModel = GROK_SESSION_OPTION_CATALOG.modelApply.removeAgentArgs!
+  const removeEffort = grokEffortOption().apply.removeAgentArgs!
 
-  it('detects a user-supplied model flag in every spelling', () => {
+  it('strips a user-supplied model flag in every spelling', () => {
     for (const tokens of [
       ['-m', 'grok-build'],
       ['-mgrok-build'],
       ['--model', 'grok-build'],
       ['--model=grok-build']
     ]) {
-      expect(modelOverride(tokens)).toBe(true)
+      expect(removeModel(tokens)).toEqual([])
     }
   })
 
   it('does not fire on a different flag or a positional that contains -m', () => {
-    expect(modelOverride(['--model-context', '8000'])).toBe(false)
-    expect(modelOverride(['summarize-my-diff'])).toBe(false)
-    expect(modelOverride(['--reasoning-effort', 'low'])).toBe(false)
-    expect(modelOverride([])).toBe(false)
+    for (const tokens of [
+      ['--model-context', '8000'],
+      ['summarize-my-diff'],
+      ['--reasoning-effort', 'low'],
+      []
+    ]) {
+      expect(removeModel(tokens)).toEqual(tokens)
+    }
   })
 
-  it('detects both effort spellings', () => {
-    expect(effortOverride(['--effort', 'low'])).toBe(true)
-    expect(effortOverride(['--reasoning-effort=low'])).toBe(true)
-    expect(effortOverride(['--effortless'])).toBe(false)
+  it('strips both effort spellings', () => {
+    expect(removeEffort(['--effort', 'low', '--reasoning-effort=high', '--keep'])).toEqual([
+      '--keep'
+    ])
+    expect(removeEffort(['--effortless'])).toEqual(['--effortless'])
   })
 
   it('drops only the overridden key from the launch record', () => {
diff --git a/src/shared/agent-session-option-catalog-grok.ts b/src/shared/agent-session-option-catalog-grok.ts
index 4f14fdbeade..3577ae036a0 100644
--- a/src/shared/agent-session-option-catalog-grok.ts
+++ b/src/shared/agent-session-option-catalog-grok.ts
@@ -1,9 +1,9 @@
-import { hasFlag } from './agent-cli-flag-detection'
 import type {
   AgentSessionOptionCatalog,
   CatalogModel,
   CatalogOption
 } from './agent-session-option-catalog-types'
+import { removeAgentArgOption } from './agent-session-option-agent-args'
 import { parseGrokModelList } from './grok-model-list-probe'
 
 // The offered slice of grok's canonical ladder, low to high. Its `none` tier is
@@ -35,7 +35,8 @@ function grokEffort(ceiling: 'high' | 'xhigh'): CatalogOption {
     },
     apply: {
       launchArgs: (value) => ['--reasoning-effort', String(value)],
-      agentArgsOverride: (tokens) => hasFlag(tokens, ['--effort', '--reasoning-effort']),
+      // Why: grok reads both spellings.
+      removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--effort', '--reasoning-effort']),
       midSession: { kind: 'command', build: (value) => `/effort ${String(value)}` }
     }
   }
@@ -67,7 +68,7 @@ export const GROK_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   ],
   modelApply: {
     launchArgs: (value) => ['-m', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['-m', '--model']),
+    removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['-m', '--model']),
     // Why: `agent-picker` would replace the whole model list with "Choose in
     // agent picker…" and never persist a model, so `-m` would never be emitted.
     midSession: { kind: 'command', build: (value) => `/model ${String(value)}` }
diff --git a/src/shared/agent-session-option-catalog-muse.ts b/src/shared/agent-session-option-catalog-muse.ts
index 6b5df60fe4d..91163ca7267 100644
--- a/src/shared/agent-session-option-catalog-muse.ts
+++ b/src/shared/agent-session-option-catalog-muse.ts
@@ -1,4 +1,3 @@
-import { hasFlag } from './agent-cli-flag-detection'
 import { removeAgentArgOption } from './agent-session-option-agent-args'
 import type { AgentSessionOptionCatalog, CatalogOption } from './agent-session-option-catalog-types'
 
@@ -22,7 +21,6 @@ const MUSE_EFFORT: CatalogOption = {
   },
   apply: {
     launchArgs: (value) => ['--reasoning-effort', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--reasoning-effort']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--reasoning-effort'])
   }
 }
@@ -34,7 +32,6 @@ export const MUSE_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   models: [],
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--model']),
     removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--model'])
   },
   unknownModelOptions: [MUSE_EFFORT]
diff --git a/src/shared/agent-session-option-catalog-omp.test.ts b/src/shared/agent-session-option-catalog-omp.test.ts
index fdac98154c6..b5bd44e32f3 100644
--- a/src/shared/agent-session-option-catalog-omp.test.ts
+++ b/src/shared/agent-session-option-catalog-omp.test.ts
@@ -116,13 +116,16 @@ describe('omp session option catalog', () => {
   })
 
   it('yields to a user --model in the launch args, in either spelling', () => {
-    const override = OMP_SESSION_OPTION_CATALOG.modelApply.agentArgsOverride!
-    expect(override(['--model', 'opus'])).toBe(true)
-    expect(override(['--model=openai/gpt-5.5'])).toBe(true)
-    expect(override(['--no-extensions'])).toBe(false)
+    const remove = OMP_SESSION_OPTION_CATALOG.modelApply.removeAgentArgs!
+    expect(remove(['--model', 'opus', '--model=openai/gpt-5.5', '--no-extensions'])).toEqual([
+      '--no-extensions'
+    ])
     // `--models` scopes Ctrl+P cycling; it does not pick a model. omp has no `-m`.
-    expect(override(['--models=anthropic/*'])).toBe(false)
-    expect(override(['-m', 'opus'])).toBe(false)
+    expect(remove(['--models=anthropic/*', '-m', 'opus'])).toEqual([
+      '--models=anthropic/*',
+      '-m',
+      'opus'
+    ])
   })
 
   it('switches mid-session with /orca-model <selector>, which omp resolves exactly', () => {
diff --git a/src/shared/agent-session-option-catalog-omp.ts b/src/shared/agent-session-option-catalog-omp.ts
index 33b870b3d7d..312b3f6306a 100644
--- a/src/shared/agent-session-option-catalog-omp.ts
+++ b/src/shared/agent-session-option-catalog-omp.ts
@@ -1,4 +1,4 @@
-import { hasFlag } from './agent-cli-flag-detection'
+import { removeAgentArgOption } from './agent-session-option-agent-args'
 import type { AgentSessionOptionCatalog, CatalogModel } from './agent-session-option-catalog-types'
 import { parseOmpModelList } from './omp-model-list-probe'
 
@@ -18,7 +18,7 @@ export const OMP_SESSION_OPTION_CATALOG: AgentSessionOptionCatalog = {
   models: [],
   modelApply: {
     launchArgs: (value) => ['--model', String(value)],
-    agentArgsOverride: (tokens) => hasFlag(tokens, ['--model']),
+    removeAgentArgs: (tokens) => removeAgentArgOption(tokens, ['--model']),
     // OMP only opens its TUI picker for /model; our extension applies the exact selector.
     midSession: { kind: 'command', build: (value) => `/orca-model ${String(value)}` }
   },
diff --git a/src/shared/agent-session-option-catalog-removers.test.ts b/src/shared/agent-session-option-catalog-removers.test.ts
new file mode 100644
index 00000000000..64262213d4e
--- /dev/null
+++ b/src/shared/agent-session-option-catalog-removers.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, it } from 'vitest'
+import { getAgentSessionOptionCatalog } from './agent-session-option-catalog'
+import { removeAgentArgOption } from './agent-session-option-agent-args'
+import {
+  removeOverriddenAgentSessionArgs,
+  resolveAgentSessionOptionLaunch
+} from './agent-session-option-launch'
+
+const removeCodexModel = getAgentSessionOptionCatalog('codex')!.modelApply.removeAgentArgs!
+
+describe('catalog removers', () => {
+  it.each([
+    [['-c', 'model=o3']],
+    [['--config', 'model=o3']],
+    [['-c=model=o3']],
+    [['-cmodel=o3']],
+    [['--config=model=o3']]
+  ])('strips Codex model config %j and yields the picked model to it', (tokens) => {
+    expect(removeCodexModel([...tokens, '--search'])).toEqual(['--search'])
+    expect(
+      resolveAgentSessionOptionLaunch('codex', { model: 'gpt-5.5' }, tokens).appliedValues
+    ).toEqual({})
+  })
+
+  it('keeps other Codex config, including effort, when stripping the model', () => {
+    const tokens = [
+      '-c',
+      'model_reasoning_effort=high',
+      '-cmodel_reasoning_effort=low',
+      '-csandbox=x'
+    ]
+    expect(removeCodexModel(tokens)).toEqual(tokens)
+  })
+
+  it('leaves everything after a terminator', () => {
+    const tokens = ['--', '-c', 'model=o3']
+    expect(removeCodexModel(tokens)).toEqual(tokens)
+  })
+
+  it('lets a chat pick replace a configured gemini model on server launches', () => {
+    expect(
+      removeOverriddenAgentSessionArgs('gemini', { model: 'gemini-2.5-pro' }, [
+        '-m',
+        'a',
+        '--model=b',
+        '-mc',
+        '--yolo'
+      ])
+    ).toEqual(['--yolo'])
+  })
+})
+
+describe('removeAgentArgOption', () => {
+  it('consumes an empty value', () => {
+    expect(removeAgentArgOption(['--model', '', '--yolo'], ['--model'])).toEqual(['--yolo'])
+  })
+
+  it('keeps a following flag', () => {
+    expect(removeAgentArgOption(['--model', '--yolo'], ['--model'])).toEqual(['--yolo'])
+  })
+})
diff --git a/src/shared/agent-session-option-catalog-types.ts b/src/shared/agent-session-option-catalog-types.ts
index 74e488e5549..fe15d5080e0 100644
--- a/src/shared/agent-session-option-catalog-types.ts
+++ b/src/shared/agent-session-option-catalog-types.ts
@@ -21,10 +21,8 @@ export type CatalogMidSessionApply =
 
 export type CatalogOptionApply = {
   launchArgs?: (value: SessionOptionValue) => string[]
-  /** Why: later free-form args win, so the launch record must discard any
-   * picker value that those args may have replaced. */
-  agentArgsOverride?: (tokens: readonly string[]) => boolean
-  /** Removes conflicting defaults before a more specific launch choice is inserted. */
+  /** Strips the free-form args that set this option. Why: later free-form args win, so
+   * anything this strips also tells the launch record to discard the picker value. */
   removeAgentArgs?: (tokens: readonly string[]) => string[]
   composedIntoModel?: true
   midSession?: CatalogMidSessionApply
@@ -75,7 +73,7 @@ export type AgentSessionOptionCatalog = {
    *
    * Known gap: "no model flag" is unverified. A user `-m` in `agentArgs` launches that
    * model while the picker, which never reads launch args, still names the CLI default.
-   * A real fix means threading `modelApply.agentArgsOverride` through to the surface. */
+   * A real fix means threading `modelApply.removeAgentArgs` through to the surface. */
   defaultModelIsCliDefault?: true
   listModels?: {
     command: string
diff --git a/src/shared/agent-session-option-launch.ts b/src/shared/agent-session-option-launch.ts
index 53df967a838..e9c5b90181d 100644
--- a/src/shared/agent-session-option-launch.ts
+++ b/src/shared/agent-session-option-launch.ts
@@ -1,5 +1,6 @@
 import type { AgentType } from './agent-status-types'
 import { findCatalogModel, getAgentSessionOptionCatalog } from './agent-session-option-catalog'
+import type { CatalogOptionApply } from './agent-session-option-catalog-types'
 import type { SessionOptionValue } from './native-chat-session-options'
 
 export type ResolvedSessionOptionLaunch = {
@@ -7,6 +8,11 @@ export type ResolvedSessionOptionLaunch = {
   appliedValues: Record<string, SessionOptionValue>
 }
 
+function isOverriddenByAgentArgs(apply: CatalogOptionApply, tokens: readonly string[]): boolean {
+  const kept = apply.removeAgentArgs?.(tokens)
+  return kept !== undefined && kept.length < tokens.length
+}
+
 export function removeOverriddenAgentSessionArgs(
   agent: AgentType,
   values: Record<string, SessionOptionValue> | null | undefined,
@@ -63,7 +69,7 @@ export function resolveAgentSessionOptionLaunch(
   const composedModelId = catalog.composeModelValue
     ? catalog.composeModelValue(modelId, modelValues)
     : modelId
-  const modelOverridden = catalog.modelApply.agentArgsOverride?.(trailingAgentArgs) === true
+  const modelOverridden = isOverriddenByAgentArgs(catalog.modelApply, trailingAgentArgs)
 
   if (catalog.modelApply.launchArgs) {
     args.push(...catalog.modelApply.launchArgs(composedModelId))
@@ -86,7 +92,7 @@ export function resolveAgentSessionOptionLaunch(
       continue
     }
     args.push(...option.apply.launchArgs(value))
-    if (!modelOverridden && !option.apply.agentArgsOverride?.(trailingAgentArgs)) {
+    if (!modelOverridden && !isOverriddenByAgentArgs(option.apply, trailingAgentArgs)) {
       appliedValues[option.id] = value
     }
   }
diff --git a/src/shared/command-option-occurrence.ts b/src/shared/command-option-occurrence.ts
index 6dee668829b..203e7252723 100644
--- a/src/shared/command-option-occurrence.ts
+++ b/src/shared/command-option-occurrence.ts
@@ -11,7 +11,7 @@ function matchesOption(token: string, aliases: readonly string[]): boolean {
 }
 
 export function findOptionOccurrence(
-  tokens: string[],
+  tokens: readonly string[],
   aliases: readonly string[],
   stopAtTerminator: boolean
 ): { index: number; consumed: number; value?: string } | null {