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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description largely restates that ("its server marks it read-only, so it runs straight away") with little added nuance. It does contribute one genuinely useful behavioral fact beyond the annotations: the return payload is attachment IDs plus URLs. Nothing is said about pagination limits or result caps beyond what the schema implies.

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?

Purpose is front-loaded in the first sentence, followed by usage context and return shape, which is a sensible ordering. The closing sentence about Royally's read-only marking is largely redundant against the annotations and could be trimmed without losing information.

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 7 optional parameters and no output schema, the description fills the key gaps: it says what is returned (attachment IDs and URLs) and how search behaves. Pagination defaults and total-count behavior are left entirely to the schema, which mostly covers it given 100% coverage.

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 including search, mime_type, page, and per_page is already documented in the schema. The description's note that "search" matches title, alt text, caption, and description duplicates the schema text verbatim rather than adding new meaning. Baseline 3 is appropriate when the schema carries the parameter burden.

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 ("Lists and searches images already in the WordPress Media Library") and clarifies the scope is the site's own uploads. It does not differentiate itself from near-identical siblings in the same family such as emcp-tools-search-images, emcp-tools-get-media, or wp_find_media, so an agent cannot tell from the description alone which of these to pick.

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 a clear usage context — find a site's own uploaded photos before reaching for stock imagery — and names the downstream consumer (add-free-widget) for the returned IDs/URLs. It stops short of explicit alternatives or when-not conditions, e.g. when to prefer search-images or get-media instead.

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