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

With no annotations provided, the description carries the burden and does well by listing the exact return fields (name, bio, birth date/place, profile image, filmography) and noting the token cost. It does not mention potential errors or rate limits, but as a read-only lookup, the provided information is sufficient.

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 description is three focused sentences: purpose, return data, and cost. It is front-loaded with the main action and avoids any unnecessary details. Every sentence adds value.

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 simple one-parameter tool with an output schema present, the description is complete: it states what is returned and the cost. It could optionally mention using the search tool to find a slug, but that is not essential. The description covers the key aspects needed for invocation.

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?

The schema already fully describes the parameter with a 100% coverage, including an example. The description repeats the example but does not add new semantic meaning beyond what the schema provides. 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?

The description uses a specific verb ('Look up') with a clear resource ('celebrity on Rotten Tomatoes') and the input method ('by slug'). It distinguishes itself from sibling tools like movie_details or search by focusing on celebrity-specific details.

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 description implies usage when you have a celebrity slug and need detailed biographical/filmography information. It does not explicitly mention alternatives or when not to use, though the context of having a slug is clear. Missing direct comparison to sibling tools like rotten-tomatoes.search.

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