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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and open-web profile is covered. The description adds that results are mixed by default across four entity types, which is useful, but says nothing about pagination depth or result ordering beyond what annotations/schema imply.

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 filler. The search capability is front-loaded and the sibling-routing guidance follows immediately.

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 described, and the sibling routing completes the picture for a search entry point. The only gap is the ambiguous type-filter semantics relative to what the schema actually permits.

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 loosely implies the type filter accepts film/person/list/tag, while the schema restricts type to 'film' and treats omission as the mixed-results path — a mild description/schema tension rather than added clarity.

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 (Search) plus the resource and its scope (Letterboxd films, people, lists, or tags, filtered by result type). It is immediately distinguishable from siblings such as letterboxd_film, letterboxd_member, and letterboxd_popular, which it names explicitly.

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 letterboxd_film or letterboxd_member once a specific result is selected, and letterboxd_popular for the popularity chart. The condition selecting each alternative is stated, not inferred.

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