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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-access profile are covered. The description adds no behavioral context beyond that – no auth requirements, rate limits, or failure modes – and its list of returned fields largely duplicates the declared output schema, so it doesn't materially extend what structured data already provides.

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 sentences with zero waste: the fetch-and-return statement is front-loaded, and the routing guidance is compactly bundled into one follow-up sentence.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. For a single-required-parameter lookup tool, the description plus structured fields give the agent everything needed to select and invoke it correctly.

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 itself supplies the slug example ('elden-ring, oppenheimer, breaking-bad'). The description only restates that lookup is by show slug, adding no format or syntax detail beyond the schema, so the baseline 3 is appropriate.

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 (Fetch) and resource (Metacritic TV details) scoped by an identifying slug, and enumerates the returned content. It distinguishes itself from metacritic_movie and metacritic_game by naming them as the tools for other media types.

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?

Explicitly routes the agent: critic/user reviews go to metacritic_tv_critic_reviews or metacritic_tv_user_reviews, discovery goes to metacritic_browse, and other media types to metacritic_movie/metacritic_game. Both the when-to-use and the alternatives are named with no inference required.

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