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

Annotations already declare readOnlyHint and openWorldHint. The description adds useful context beyond them: the data source is 'credential-free public AniList data', results are 'paginated', and the returned summary fields are listed. It does not discuss rate limits or freshness, keeping it short of a 5.

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?

Four compact sentences, front-loaded with purpose and return shape, then source, then parameters, then the sibling routing. No wasted text.

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 annotations covering the safety profile and an output schema defining return values, the description only needs to orient the agent, which it does. The per_page parameter is left entirely to the schema, a minor gap given pagination is mentioned only implicitly.

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 the schema already documents all three parameters, including per_page and its clamp. The description reinforces query with a concrete example ('Frieren'), which is mildly helpful but does not exceed the schema baseline.

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+resource ('Searches anime and manga characters by name') and explicitly routes to the sibling anime_character for the detail lookup. An agent can distinguish it from anime_search, anime_title, and anime_title_characters without opening schemas.

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?

Names the alternative ('Use anime_character to get an anime/manga character'), making the search-vs-detail split explicit. However, it does not disambiguate against other plausible alternatives in this crowded namespace, such as anime_title_characters or manga_search.

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