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. The description's only added behavioral content is the response shape (total, echoed filters, page availability, ranked titles), which largely duplicates the existing output schema, so it adds modest value.

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?

Two tight sentences with the core action front-loaded and the routing hint placed second where it belongs. No padding, though the inaccurate filter list marginally wastes the first sentence's descriptive budget.

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 an output schema present, return values need not be explained further, and the 100%-covered schema documents all filters. For an 8-param, all-optional tool the description is essentially complete, its main flaw being the mismatched filter names rather than missing information.

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 8 parameters thoroughly. The description's param claims ("media type and minimum score filters") do not match the actual parameters (genre, format, season, status, season_year, sort, page, per_page), and "minimum score" has no equivalent at all, making the description mildly misleading rather than additive.

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 clear verb and resource ("Get sorted anime rankings") and distinguishes itself from title lookup by routing away from search. However, it advertises "media type and minimum score filters" that do not correspond to any parameter in the schema, so the stated scope is partially inaccurate.

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?

It explicitly says to use this "to compare top-rated or popular anime rather than search by title," which effectively names the alternative (anime_search) and the condition selecting it. It stops short of any exclusion beyond that single contrast, e.g. versus anime_airing_schedule.

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