fix: let an mcp server entry be named by the path the roster shows

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/windmill-worker/src/ai_executor.rs

@@ -246,12 +246,6 @@ fn overlay_tool_inputs(
     }
 }
 
-/// Write a linked step's own inputs over the brain its agent supplied.
-///
-/// Called only after the resource has been interpolated: these values are caller-controlled and
-/// `build_args_map` has already resolved them, so passing them through it again would expand
-/// contextual values — `$WM_TOKEN` in a user message would reach the model provider.
-///
 /// The roster a run advertises, given the tool names it enabled, plus the resource paths of the
 /// MCP entries it named outright — those enable every tool of that server, which only
 /// `load_mcp_tools` can enumerate.
@@ -282,9 +276,13 @@ fn narrow_roster(
                 .is_some_and(|s| enabled.iter().any(|n| n == s));
             match &t.value {
                 ToolValue::Mcp(mcp) => {
+                    // An MCP entry is added with no summary and the roster displays it by its
+                    // resource path, so that path is the only name the form can offer for it. Match
+                    // it too, or naming one tool would be the sole way to keep a whole server.
+                    let path = mcp.resource_path.trim_start_matches("$res:");
+                    let named = named || enabled.iter().any(|n| n == path);
                     if named {
-                        enabled_mcp_paths
-                            .insert(mcp.resource_path.trim_start_matches("$res:").to_string());
+                        enabled_mcp_paths.insert(path.to_string());
                     }
                     named || names_a_server_tool
                 }
@@ -2056,6 +2054,22 @@ mod tests {
         let (kept, paths) = narrow_roster(roster(), Some(&["mcp_github_create_issue".to_string()]));
         assert_eq!(names(&kept), ["github"]);
         assert!(paths.is_empty());
+
+        // An MCP entry is added with no summary, and the form offers it by the path the roster
+        // displays it as. Without this the only way to keep such a server would be naming one of
+        // the tools it has not been asked for yet.
+        let unnamed = || {
+            vec![AgentTool {
+                summary: None,
+                ..mcp("c", "github", "$res:u/test/gh")
+            }]
+        };
+        let (kept, paths) = narrow_roster(unnamed(), Some(&["u/test/gh".to_string()]));
+        assert_eq!(kept.len(), 1);
+        assert_eq!(paths.into_iter().collect::<Vec<_>>(), ["u/test/gh"]);
+        let (dropped, paths) = narrow_roster(unnamed(), Some(&["u/test/other".to_string()]));
+        assert!(dropped.is_empty());
+        assert!(paths.is_empty());
     }
 
     /// The two sides of the server-entry match are different types, and getting it wrong advertises

docs/feature-telemetry.md

@@ -4,7 +4,7 @@
 anonymous usage-stats payload. It answers "does anyone use this, and which variant do they pick"
 without any identifying data leaving the instance.
 
-It currently carries 49 registered actions across eighteen features (`ai_session`, `ai_chat`,
+It currently carries 50 registered actions across eighteen features (`ai_session`, `ai_chat`,
 `ai_fix`, `ai_agent`, `ai_agent_eval`, `app_sandbox`, `datatable`, `flow_editor`, `flow_run`,
 `flow_step`, `home`, `run_form`, `debugger`, `trigger`, `command_script`, `hub_script`,
 `usage_meter`, `sso_groups_claim`). Nearly all of the

frontend/src/lib/components/flows/content/AiAgentStepInputs.svelte

@@ -46,7 +46,7 @@
 	import { Plus, X } from 'lucide-svelte'
 	import type { PickableProperties } from '../previousResults'
 	import type { FlowCopilotContext } from '$lib/components/copilot/flow'
-	import type { AgentTool } from '../agentToolUtils'
+	import { toolDisplayName, type AgentTool } from '../agentToolUtils'
 	import {
 		AGENT_FIELDS,
 		AGENT_FIELD_GROUPS,
@@ -168,7 +168,12 @@
 	// field's shape from; `flowInfers` hands every step its own copy, so this stays this step's.
 	// A linked step gets the resource's roster here, which is the one it narrows.
 	$effect(() => {
-		const names = tools.map((tool) => tool.summary).filter((name): name is string => !!name)
+		// By the name the roster shows, not the summary alone: an MCP entry is added without one and
+		// displays as its resource path, so keying on `summary` would leave a whole server with no
+		// name to pick. `narrow_roster` matches that path for the same reason.
+		const names = tools
+			.map((tool) => toolDisplayName(tool))
+			.filter((name): name is string => !!name)
 		const properties = schemaProperties
 		untrack(() => {
 			const list = properties['enabled_tools']?.oneOf?.find((variant) => variant.title === 'only')