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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered by structured data. The description adds nothing behavioral — no note on the extra fetch triggered by the mal enrichment or any rate/latency caveat, even though that detail lives only in the schema parameter text.

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 short, front-loaded sentence with zero filler. It is efficient, though arguably terse rather than deliberately minimal, which is captured under completeness rather than conciseness.

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 a full output schema, 100% parameter coverage, and readOnly/openWorld annotations, the description's remaining obligations are small. Still, for a widely-siblinged detail tool it offers no routing guidance to related tools, leaving a clear but minor gap.

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%, and the mal parameter's description richly explains the enrichment behavior and the omitted case. The description itself contributes no additional parameter meaning, so the baseline of 3 applies.

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?

The fragment 'Anime detail by AniList id' identifies the resource (anime) and the lookup key (AniList id), which implicitly distinguishes it from anime_search. However, it lacks a verb and never names siblings, so an agent must infer that this is the detail-by-primary-key tool rather than a search tool.

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?

There is no explicit when-to-use guidance and no mention of alternatives such as anime_search or anime_title_characters for follow-up data. The only hint is the implicit precondition that you must already have an AniList id, which an agent must derive from the schema.

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