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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered by structured data. The description adds no extra behavioral context such as what a missing/invalid id yields; with an output schema present, return-shape disclosure is not required, so a 3 is appropriate.

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 compact sentence with no padding; the identifying parameter is front-loaded. It is arguably too terse to earn a 5, but nothing is wasted.

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 one-parameter detail lookup with an output schema and read-only annotations, the description plus structured fields cover what an agent needs to call it correctly. Only the routing to sibling search tools is left implicit.

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 coverage is 100% and the schema description already documents the id type, numeric format and an example. The description only restates that the lookup is keyed by AniList id, adding no syntax or constraint detail beyond the schema.

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 pair (character detail) plus the domain (anime/manga) and the keying identifier (AniList id), which distinguishes it from search-style siblings. It stops short of explicitly naming the alternative lookup tools, so it is clear but not sibling-differentiated in the strongest sense.

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?

'By AniList id' implies the usage condition (you must already have a numeric AniList character id), and the existence of anime_character_search as a sibling makes the retrieval-vs-search split inferable. No explicit when/when-not statement or prerequisite (e.g. that the id must come from a search first) is given.

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