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

Annotations already declare readOnlyHint/idempotentHint, so the 'read-only, runs straight away' line is largely redundant; the real value is the 100-item pagination ceiling and the returned field list, which the annotations cannot convey. No auth, rate-limit, or ordering caveats are disclosed, but none are essential for a safe read.

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 return fields, then the filter/pagination guidance in a compact sequence with no fluff. The parenthetical site ID and the 'Through Royally: read-only' trailer are boilerplate the reader must skip past, keeping it off a 5.

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 6 optional params, no output schema, and a read-only profile, the description covers what is returned, how to narrow results, how to paginate, and the 100-item boundary. An agent has everything needed to call it correctly without further discovery.

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 every parameter is already documented in the schema, including the same `empty`/`present` alt-text semantics and offset behavior. The description restates this guidance with slightly more framing ('instead of paging the whole library') but adds no syntax or format detail beyond the schema — baseline 3.

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 ('List media library attachments') and enumerates the returned fields, so the agent knows exactly what the tool yields. It does not name the closely related siblings (wp_find_media, wp_get_media_item, wp_count_media), so the agent has to infer which one to pick for a single-item lookup vs. a list.

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 concrete routing rules inside the tool: use `search` instead of paging the whole library, use `alt_text` for alt-audit questions, and paginate with offset past 100 items. It stops short of explicitly excluding the sibling tools (e.g., find_media or get_media_item) that an agent could otherwise reach for.

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