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

Annotations already flag readOnlyHint=false and destructiveHint=true, so the description adds nothing about what makes this destructive (e.g., whether omitted fields are cleared or preserved), what permissions are required, or whether changes are reversible. For a mutation tool with a destructive hint, this is a notable gap.

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 front-loaded sentence with no filler. It is efficient, though its brevity contributes to the gaps in other dimensions.

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 destructive mutation with no annotations explaining behavior, no output schema, and 0% schema coverage on five parameters, the description is too thin. It omits the required ID, the effect of omitted fields, and any error or 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 description coverage is 0%, so the description must compensate; it names four of the five parameters (title, caption, description, alt) but never mentions the required ID parameter or explains omission semantics. Field mapping is useful but leaves critical semantics 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 (update) and resource (Media Library item) plus the exact fields affected, so it is distinguishable from wp_upload_media and wp_update_post. It stops short of differentiating the intended item scope more explicitly, but the purpose is 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?

Naming 'Media Library item' implies this operates on existing attachments rather than new uploads, which implicitly separates it from wp_upload_media. However, there is no explicit when-to-use guidance, no mention of prerequisites, and no named alternative for non-media post updates.

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