Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false and openWorldHint=false; the description adds material context beyond that — the auth requirement (Picorn access token), the implicit side effect of creating a project when the workspace params are omitted, and the mutation's output identity (campaignId plus one ideaId per idea). This is more than the annotations convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Dense but front-loaded: purpose first, then the workspace decision, then the return values, then the downstream workflow. Every sentence adds operational information — the parenthetical "(no model is called)" and the access-token note both prevent a wrong assumption.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description helpfully states what is returned (campaignId, ideaId per idea), and it covers prerequisites and the next tool in the chain. It stops short of describing the boundary conditions an agent might hit, such as the 50-idea cap or how ideas are handled if the array is omitted.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 20%, so the description must compensate — and it does for the two hardest parameters, explaining the source of workspaceProjectId/workspaceProjectKey and the semantics of omitting both. It does not explain the ideas array's fields (hook, cta, angle, title, caption) or the topic/description semantics beyond the general phrase "post ideas," leaving part of the low-coverage schema undocumented.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ("Create a campaign") and immediately scopes it as built "from agent-authored post ideas (no model is called)," which distinguishes it from generation-oriented siblings like picorn_generate_image. The clarification that no model is invoked separates it from anything that produces content on the server side.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit conditional guidance: pass workspaceProjectId + workspaceProjectKey from picorn_projects_create, or omit both to create a new project named after the topic. It also names the follow-up step (create post files, then picorn_posts_schedule), so the agent knows both prerequisites and downstream alternatives without inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.