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

Annotations already cover readOnlyHint and openWorldHint, and the description adds real value beyond them: the availability precondition that only authors with an active listing have a page, and a pointer to the about_these_numbers field that documents the returned metrics.

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?

A single dense but front-loaded sentence plus a clarifying second sentence. Every clause carries information, though the field enumeration is packed tightly.

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 does the work of describing what a page contains and where the numbers are explained (about_these_numbers). Combined with the availability caveat, it is complete enough to call the tool correctly, missing only auth/permission 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?

Schema coverage is 50% — author_id has no schema description, and the description explicitly defines it as listing.author.id, which is the key semantic an agent needs. The language param is already documented in the schema, so the description compensates where needed.

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 resource (author profile behind a listing) and enumerates the fields returned: time on the board, reply time, confirmed deals, AI-agent answering, work links, active listings. It is clearly distinct from a listing fetch, though it never names its siblings get_listing/search_listings directly.

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?

Usage is implied (look up who is behind a listing) and one useful precondition is given — only authors with an active listing have a page. There is no explicit when-to-use-vs-alternative guidance against get_listing or search_listings.

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