create_thread

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It mentions 'Requires authentication' and 'Posts are automatically chained together with proper reply structure,' which are useful but insufficient. It does not discuss error states, rate limits, or what happens on failure, missing opportunities for greater transparency.

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?

The description is concise at 4 sentences, with the core purpose front-loaded in the first sentence. Every sentence adds value: purpose, behavior (chaining), use case, and authentication requirement. No wasteful words or redundancy.

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?

Given the moderate complexity (array of posts with chaining) and no output schema, the description covers essential aspects: purpose, chaining behavior, authentication, and use case. It does not describe the return value (e.g., thread URI) or error cases, but it is largely complete for a create operation. A brief note on the response format would elevate it further.

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 0%, so the description must compensate. However, it does not explain the parameters beyond what the schema already shows. It mentions 'posts' are chained but gives no details on the contents of each post (text, langs) or the top-level langs parameter. This leaves the agent without meaningful guidance on how to structure the inputs.

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?

The description clearly states it creates a multi-post thread with automatic chaining, distinguishing it from single-post creation tools like create_post. It explicitly mentions the AT Protocol and the use case for longer content, making the purpose specific and unambiguous.

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?

The description provides a clear when-to-use guideline: 'Useful for longer-form content that exceeds the 300-character limit.' This implies that for shorter content, single-post tools are appropriate. However, it does not explicitly mention alternatives like create_post or create_rich_text_post, which weakens the guidance slightly.

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