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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds real context beyond them with 'Credential-free public Metacritic data,' disclosing the auth requirement. It doesn't mention rate limits or freshness, but for a read-only detail tool this is solid added 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?

Front-loads the return contents before the credential note, parameter requirement, and routing hint, so the key value proposition leads. The 'slug:' fragment is slightly awkward but each clause carries information; only minor trimming is possible.

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, and the description covers purpose, auth, and an alternative tool. The only gap is richer usage context relative to metacritic_tv/game lookups and an example ('breaking-bad') that is actually a TV title for a movie tool, a small inconsistency.

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%, so the schema already documents the single slug parameter. The description repeats the slug requirement and examples verbatim without adding format/syntax detail beyond the schema, so the baseline 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?

States a specific verb ('Returns') and resource ('normalized Metacritic movie'), then enumerates the payload (Metascore, user score, genres, cast/crew, rating, runtime, release date, IMDb id, trailer). The resource name cleanly distinguishes it from metacritic_game and metacritic_tv siblings without opening their 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?

Explicitly routes the agent: 'Use metacritic_movie_critic_reviews to list a Metacritic movie's critic reviews,' naming the sibling and the condition that selects it. No when-not guidance (e.g. vs. full detail lookup), so it stops short of 5.

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