Reply to a post

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

Beyond the destructiveHint annotation, the description reveals that replies are public immediately, count against a 1,000-reply daily quota, and require confirm:true. The schema further adds that Threads has no edit endpoint and no unsend, giving the agent a clear picture of irreversibility.

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?

Two concise sentences front-load the action and immediately state the most important behavioral caveats. There is no filler or unnecessary repetition of schema content.

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?

The description captures the essential behavioral constraints and the schema covers the parameters well, so an agent can invoke the tool correctly. It does not describe the response shape or explain how to obtain post IDs, but those are minor gaps given the schema and sibling context.

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 86% schema description coverage, the input schema already documents id, text, account, confirm, image_url, and video_url. The description adds the confirm requirement but no new per-parameter meaning, so it remains at the high-coverage baseline of 3.

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 states a specific verb ('Publish'), a specific resource ('a reply to a Threads post'), and scope ('yours or anyone's'). This clearly distinguishes it from create_post, quote_post, and repost without requiring the agent to inspect sibling schemas.

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 provides clear context: use this tool when the goal is to reply to an existing Threads post, not to create a new post or quote/repost. It does not explicitly name alternatives or state when not to use it, so it falls just short of a 5.

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