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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds a key behavioral detail: returns only top 15 credits by votes, not everything. This is valuable context that informs the agent about response scope and potential incompleteness. No contradiction with annotations.

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 concise sentences: first states what the tool provides, second gives usage examples and a critical limitation. No filler, front-loaded with the main purpose, and every sentence earns its place.

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?

Given no output schema, the description covers return contents (bio, photo, credits) and the top-15 limitation. It doesn't address ambiguous names or pagination, but for a simple person lookup this is adequate. With annotations covering safety and schema covering parameters, the description is sufficiently complete.

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 has 100% coverage with clear descriptions for both 'query' and 'language'. The tool description adds no extra parameter information beyond what the schema already provides, so baseline 3 is appropriate.

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 clearly that it returns person info (bio, photo, acting/directing credits) and gives explicit example queries like 'what else did the Dune director make'. This distinguishes it from movie-centric tools like movies_details or movies_search. The resource and scope are unambiguous.

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?

Provides explicit use cases: actor filmography and director questions. It also notes the 'top 15 credits' limitation, implying when a more complete result might be needed. However, it doesn't name alternative tools explicitly or state when NOT to use it beyond that limitation.

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