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

Annotations already cover read-only and open-world nature, so the description focuses on scope: reviews included are only 'representative embedded audience reviews', which usefully signals partial coverage and prevents the agent from treating this as an exhaustive review source. It also disambiguates the two optional params with a mutual-exclusion rule the schema does not express.

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?

Three short sentences: capability first, input constraint second, sibling routing last. No filler, no restatement of the tool name or of annotation-declared safety.

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 no explanation, and the description still summarizes the key content. Complete enough to call correctly, with the only omission being how to acquire a valid path or URL.

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 baseline is 3; the description earns above baseline by adding the mutual-exclusion constraint ('exactly one') and the '/m/...' path shape, neither of which appears in the schema where both properties are listed as optional with no oneOf/required rule.

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?

Specific verb + resource ('Fetch details for one Rotten Tomatoes movie') followed by an explicit payload inventory (cast, critic and audience scores, metadata, embedded audience reviews). It is immediately distinguishable from rottentomatoes_movie_reviews, which it names.

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 review-seeking callers to rottentomatoes_movie_reviews and states the 'pass exactly one' input constraint, which is real decision guidance. It doesn't say where to obtain a path/URL in the first place (rottentomatoes_search or rottentomatoes_movies), leaving a small gap before the tool can be invoked.

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