feat(core): stronger background wording for image_generate, chat-only subagent models

Author: rekram1-node

packages/core/src/tool/plugin/image-generate.ts

@@ -35,7 +35,7 @@ const EXTENSIONS: Record<string, string> = {
 const PREFERRED_FAMILIES = ["gpt-image", "gemini-flash", "gemini-pro", "grok", "flux"]
 
 export const description =
-  "Generate or edit an image. Pass images to edit them or to guide style and subject. To make several images, call the tool once per image with distinct prompts. Omit model to use the default. Runs in the background: the call returns right away and you are notified when the image is saved; then use the read tool on its path to view it, and mention the path to the user. Don't poll or wait for it. Each call costs money, so don't regenerate unless asked or the result is clearly wrong."
+  "Generate or edit an image. Pass images to edit them or to guide style and subject. To make several images, call the tool once per image with distinct prompts. Omit model to use the default. Runs in the background: the call returns right away and you are notified automatically when the image is saved or fails. DO NOT sleep, poll, or check whether the file exists while it runs; continue with other work or end your response. After the notice, use the read tool on the path to view the image and mention the path to the user. Each call costs money, so don't regenerate unless asked or the result is clearly wrong."
 
 export const Input = Schema.Struct({
   prompt: Schema.String.check(Schema.isMinLength(1)).annotate({
@@ -336,7 +336,12 @@ export const Plugin = {
               yield* notifyWhenDone(context.sessionID, job.id, requested)
               return {
                 output: { path: requested, model: ref },
-                content: `Image request started in the background with ${ref}. Output path: ${requested}. You will be notified when it finishes or fails. Do not poll; use the read tool on the path after completion.${resolved.note ?? ""}`,
+                content: [
+                  `Image request started in the background with ${ref}. It will be saved to: ${requested}${resolved.note ?? ""}`,
+                  "You will be notified automatically when it finishes or fails.",
+                  "DO NOT sleep, poll, check whether the file exists, or request the same image again while it runs.",
+                  "Work on other tasks, or briefly tell the user what you started and end your response.",
+                ].join("\n"),
                 metadata: { path: requested, model: ref, jobID: job.id },
               }
             }).pipe(

packages/core/src/tool/plugin/subagent.ts

@@ -35,7 +35,7 @@ export const Input = Schema.Struct({
   prompt: Schema.String.annotate({ description: "The task for the subagent to perform" }),
   model: Schema.optionalKey(Schema.String).annotate({
     description:
-      'NEVER set this unless the user explicitly asks for a particular model or variant. The value is written as "providerID/modelID", or "providerID/modelID#variant" to include a variant. Do not guess the ID: look the model up with the models tool, filtering to your own provider first.',
+      'NEVER set this unless the user explicitly asks for a particular model or variant. It must be a chat model; image and decision models can\'t run subagents. The value is written as "providerID/modelID", or "providerID/modelID#variant" to include a variant. Do not guess the ID: look the model up with the models tool, filtering to your own provider first.',
   }),
   sessionID: Schema.optionalKey(SessionSchema.ID).annotate({
     description:
@@ -83,10 +83,16 @@ export const Plugin = {
       const model = (yield* models.available()).find(
         (model) => model.providerID === ref.providerID && model.id === ref.id,
       )
-      if (model === undefined)
+      if (model === undefined) {
+        const other = (yield* models.available(["image", "decision"])).find(
+          (model) => model.providerID === ref.providerID && model.id === ref.id,
+        )
         return yield* new ToolFailure({
-          message: `Model "${ref.providerID}/${ref.id}" is not available. Use the models tool to see what is available.`,
+          message: other
+            ? `Model "${ref.providerID}/${ref.id}" is ${other.type === "image" ? "an image" : "a decision"} model; subagents need a chat model. Use the models tool to find one.`
+            : `Model "${ref.providerID}/${ref.id}" is not available. Use the models tool to see what is available.`,
         })
+      }
       if (ref.variant !== undefined && !model.variants.some((variant) => variant.id === ref.variant))
         return yield* new ToolFailure({
           message:

packages/core/test/tool-image-generate.test.ts

@@ -229,7 +229,12 @@ describe("image_generate", () => {
       expect(result.content).toEqual([
         {
           type: "text",
-          text: `Image request started in the background with test/painter. Output path: ${file}. You will be notified when it finishes or fails. Do not poll; use the read tool on the path after completion.`,
+          text: [
+            `Image request started in the background with test/painter. It will be saved to: ${file}`,
+            "You will be notified automatically when it finishes or fails.",
+            "DO NOT sleep, poll, check whether the file exists, or request the same image again while it runs.",
+            "Work on other tasks, or briefly tell the user what you started and end your response.",
+          ].join("\n"),
         },
       ])
       expect(yield* notice(result)).toBe(

packages/core/test/tool-subagent.test.ts

@@ -184,6 +184,12 @@ const withSubagent = (location: Location.Ref) =>
           model.variants = [{ id: Model.VariantID.make("fast") }]
         })
         editor.models.update(Provider.ID.make("test"), Model.ID.make("plain"), () => {})
+        editor.models.update(Provider.ID.make("test"), Model.ID.make("painter"), (model) => {
+          model.type = "image"
+        })
+        editor.models.update(Provider.ID.make("test"), Model.ID.make("classifier"), (model) => {
+          model.type = "decision"
+        })
       }),
     ).pipe(Effect.provide(locations.get(location)))
     yield* Agent.Service.use((agents) =>
@@ -714,6 +720,14 @@ describe("SubagentTool", () => {
             ["test/missing", 'Model "test/missing" is not available. Use the models tool to see what is available.'],
             ["test/override#slow", 'Variant "slow" is not available for "test/override". Available: fast.'],
             ["test/plain#high", 'Model "test/plain" has no variants. Omit the variant.'],
+            [
+              "test/painter",
+              'Model "test/painter" is an image model; subagents need a chat model. Use the models tool to find one.',
+            ],
+            [
+              "test/classifier",
+              'Model "test/classifier" is a decision model; subagents need a chat model. Use the models tool to find one.',
+            ],
           ] as const
           for (const [model, message] of failures) {
             expect(yield* call(`call-${model}`, { model })).toEqual({