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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful context by explicitly noting that both sent and queued posts are included and that counts by status are returned, going beyond what annotations provide.

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 a single sentence that immediately states the core purpose and then lists key output attributes. It is concise, front-loaded, and contains no filler, making it efficient for an agent to parse.

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 an output schema present and annotations covering safety, the description provides a solid high-level overview of what is returned. It does not explicitly state that it returns a list, but that is implied by the verb 'list' and the schema. Missing details like error conditions are minor for a read-only listing 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?

The schema provides complete descriptions for both parameters (limit and offset), including defaults, ranges, and ordering. The description adds no additional parameter-specific information, so it relies on the schema's coverage, which is sufficient.

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 the action (list) and resource (posts), and specifies scope ('every post Siren sent or queued') along with the returned fields (platform, status, live URL, time, counts). This distinguishes it from other list tools targeting different resources like films or media, making its purpose 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 implies use for viewing posts, but offers no explicit guidance on when to choose this over alternatives or any exclusions. With many sibling list tools, a brief mention of when to use this tool (e.g., 'for post history') would improve clarity, but the resource name itself conveys primary usage.

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