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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuinely new context beyond annotations: 'Credential-free public Letterboxd data' tells the agent no auth is required, and the limit bounds (default 10, max 50) signal output size constraints.

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?

The purpose is front-loaded and the sentences are short and scannable with no filler. The telegraphic fragments for slug and limit are efficient, though the parameter notes could be integrated more smoothly.

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 re-explained, and annotations cover the safety profile. The description supplies purpose, auth posture, and per-parameter bounds, leaving little an agent needs missing for a simple three-parameter read tool.

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% and all three parameters (role, slug, limit) are documented in the schema. The description's restatements of slug and limit duplicate the schema rather than adding new meaning, 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?

The opening sentence names a specific verb (returns), resource (a person's Letterboxd filmography), and scope (for a credit role), which lets an agent distinguish it from letterboxd_member or letterboxd_film. It stops short of a full 5 because it does not explicitly contrast itself with the closest siblings; the letterboxd_film mention is a follow-up hint rather than a differentiation.

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?

Usage is only implied: an agent can infer it retrieves a person's credits, but there is no statement of when to prefer this over letterboxd_search or letterboxd_member, and no prerequisites or exclusions. The 'Use letterboxd_film' line is a next-step routing hint, not an alternative-selection rule.

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