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

Adds behavior the annotations cannot convey: this is a public endpoint that answers anonymously, so a successful response does not prove the app password is valid. It names the exact error payloads (wp_timeout, wp_unreachable) and the remedy, which is precisely the kind of context an agent needs before trusting the result.

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?

Front-loaded with the action and pagination constraint, then the response shape, then the auth caveat and error handling. Every sentence carries information an agent cannot get from the schema or annotations.

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?

Covers auth caveats, failure modes and the workspace fallback, which is what makes this definition safe to call. The gap is the undocumented 'search' parameter; the return-shape sentence is redundant given the output schema exists but is not harmful.

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 0%, so the description must compensate, and it only partly does: it documents the per_page ceiling of 100 and the workspace-optional-when-single-site rule. The 'page' and especially 'search' parameters get no explanation at all, leaving half the surface undocumented.

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?

States a specific verb and resource: listing files from the WordPress media library, paginated with per_page capped at 100. The resource is clearly distinct from siblings like wp_upload_media or wp_delete_media, though the description never names an alternative explicitly.

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?

Gives operational guidance (check auth via wp_site_health, retry on wp_timeout/wp_unreachable) but no statement of when to choose this over another listing tool or any prerequisites for the call itself. Usage context is implied by the resource, not spelled out.

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