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

Annotations already declare a non-idempotent, non-destructive, open-world write. The description adds important behavioral context: platform IDs must be used exactly as returned, and there is a human-approval requirement before sending. It does not describe rate limits or error behavior, but with annotations covering safety, this is a solid addition.

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?

Three sentences, front-loaded with the purpose, followed by precise usage and approval instructions. Every sentence earns its place, with no redundancy or fluff.

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?

For a write operation with no output schema and annotations covering safety profiles, the description provides sufficient context: what it does, where to get IDs, and the approval workflow. It could mention whether the reply is publicly visible or what a success response contains, but those are minor omissions.

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 100%, so the baseline is 3. The description adds meaningful guidance beyond the schema: the IDs are platform ids, not oriiion post numbers, and must be used exactly as returned by list_comments. This helps prevent misuse of the parameters.

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 ('Reply') and resource ('a comment on one of the user's social media posts'), making the action clear. It does not explicitly differentiate from similar siblings like reply_to_review, but the resource distinction is inferable.

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 gives clear workflow guidance: source IDs from list_comments, use them exactly, and show the reply text to the user before sending unless already approved. It lacks explicit when-not-to-use guidance or named alternatives, but the context is well-established.

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