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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-web profile is covered by structured data. The description adds nothing beyond that: no indication of what the "detail" payload contains, whether the slug must be exact, or how missing films behave.

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?

At three words it is certainly terse and front-loaded, but this is under-specification rather than disciplined conciseness; nothing beyond the name is communicated.

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 described. However, for a lookup tool whose name is the only guidance, the description should at least signal that it returns full film metadata for a single film, which it does not.

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% — the single slug parameter is fully documented with an example ('parasite-2019') — so baseline 3 applies. The description adds no extra semantics about slug format or resolution.

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?

"Letterboxd film detail" effectively restates the tool name (letterboxd_film) plus the word "detail"; it supplies no verb and no scope. It also does nothing to separate a film lookup from the many sibling film-scoped tools (letterboxd_film_reviews, letterboxd_film_similar, letterboxd_film_rating_histogram).

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?

There is no when-to-use guidance and no named alternative. An agent must infer from the name alone whether to call this versus letterboxd_search to resolve a slug first, or the per-film review/similar tools.

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