Reply on Threads

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

Annotations indicate this is a write operation (readOnlyHint=false) but not destructive. The description adds critical behavioral context: it publishes publicly under the brand's account and requires user confirmation. This goes beyond annotations by explaining the irreversible public impact and the need for user consent.

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 two sentences with no redundancy. It front-loads the primary purpose and immediately adds the crucial warning about public publication and user consent. Every word earns its place.

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 could mention the response format (e.g., success or error details), but the tool is straightforward: it posts a reply. The critical behavioral guidance about user confirmation is present, and the parameter semantics are fully covered by the schema. Missing minor details like rate limits or specific platform restrictions, but these are not clearly necessary for a 2-param tool.

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 coverage is 100%, so both parameters are already described in the schema. The description adds no extra detail about the parameters beyond confirmation that they are needed. The baseline of 3 is appropriate when the schema covers the parameters adequately.

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 ('Post a reply') and resource ('a Threads post'), and clarifies it can be the brand's own or someone else's. This clearly distinguishes it from sibling tools like list_threads_replies, hide_thread_reply, and delete_thread.

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 does not explicitly state when to use this tool vs alternatives, though the interaction with list_threads_posts or list_threads_replies is implied by the context. It lacks explicit guidance on when not to use it or mentions of alternatives like comment_on_meta_post for cross-platform replies.

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