Post a thread

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

Annotations already flag destructiveHint=true and readOnlyHint=false. Beyond those, the description adds valuable behavioral context: parts are fully validated before publication ('a thread never half-publishes'), media/quote/reply apply only to the first post, and the posting is public immediately. This goes beyond the annotations and helps the agent understand side effects and atomicity.

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 about four sentences and about 60 words. It front-loads the main purpose, then adds atomicity, scoping, and confirmation in a logical order. Each sentence serves a distinct factual purpose with no redundancy or filler.

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 this is a complex tool with 9 parameters and no output schema, the description covers the most important runtime behaviors: atomic publish, confirmation requirement, and how first-post-specific arguments behave. It probably could mention that it can also start a thread as a reply (reply_to) or that it requires an authenticated account, but these are either in the schema or inferable from sibling tools. Overall it's sufficiently complete.

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?

With 89% schema coverage, the schema already documents most parameters. The description adds key semantic clarification: every part must be within the 300-character limit, and media, quote, and reply controls all apply to the first post. This is meaningful beyond the schema, which does not state that scoping. It also re-emphasizes the confirm parameter requirement.

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 begins with a specific verb and object: 'Publish several posts as one thread', which makes it immediately clear what the tool does. It also adds the structural detail that posts 'reply to the last' and explicitly draws a distinction from a single-post tool, so an agent would not confuse it with create_post.

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?

It states when to use the tool implicitly (for a multi-post thread) and gives concrete usage constraints: media, quotes and reply controls only apply to the first post, and the tool 'needs confirm: true' because it publishes publicly. It doesn't explicitly name the alternative (create_post) or say when not to use this tool, but the context is clear enough.

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