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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so the safety bar is lower. The description still adds genuine value by disclosing the return shape (cinemas with session times, format, language) in the absence of an output schema, plus the movies_enabled dependency and a written-language detail (Dublado/Legendado).

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: scope first, then return shape, then prerequisite. Every clause carries information and nothing is buried or repeated.

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?

For a 2-parameter read with no output schema, the description supplies the two things an agent cannot infer: what comes back and the site-level feature gate. Minor residual gaps (behaviour when movies_enabled is off, how 'this neighborhood' is resolved) keep it from a 5.

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 both parameters and the YYYY-MM-DD / today-BRT default are already documented. The description restates 'for a given date' and 'a specific movie' without adding format or edge-case semantics, 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 and resource (get showtimes) with scope: one movie, cinemas in this neighborhood, a given date. That makes the tool's job unmistakable. It does not name a sibling or contrast itself with a near-neighbour like get_availability, so it falls short of a 5.

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?

The prerequisite 'Requires movies_enabled on this site' is a real usage condition, and 'for a specific movie' implies a slug sourced elsewhere (list_movies appears only in the schema). There is no explicit when-not-to-use or alternative routing, so guidance is implied rather than stated.

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