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 known. The description usefully discloses the input constraint (exactly one of id/url) but says nothing about rate limits, freshness, or completeness of the aggregates. Adequate but not rich.

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, no waste: the first enumerates the returned data, the second states the input constraint and the sibling alternative. Front-loaded and efficient.

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, the description needn't explain return values, and it does cover the key input caveat and a relevant alternative. It is essentially complete for a simple two-param read tool, missing only deeper behavioral notes that the annotations largely cover.

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 both parameters are already documented. The description adds the mutually exclusive constraint ('exactly one of id or url'), which is a meaningful semantic not stated in the schema. Baseline 3 is appropriate given the schema does the heavy lifting.

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 enumerates exactly what the resource contains: aggregate rating, vote count, ten rating buckets, and country rating summaries. This makes the tool's output scope clear, though it doesn't explicitly distinguish itself from unnamed sibling rating tools like imdb_title (the only named sibling is imdb_title_reviews).

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 names the alternative 'imdb_title_reviews' and what it retrieves, and states the exclusivity constraint 'Pass exactly one of id or url'. However it doesn't give a positive when-to-use condition, only a disambiguation against one sibling among many.

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