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

No annotations are provided, so the description must disclose behavioral traits. While it implies a read-only calculation, it does not explicitly state that the tool is safe, idempotent, or any side effects. The context of it being a calculator suggests no destructive actions, but the description could be more transparent.

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 very concise—one sentence plus a brief reference to related tools. It is front-loaded with the primary action and resource, making it easy for an agent to quickly understand its purpose.

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?

The tool is simple with one parameter and an output schema (not shown). The description does not explain the return values, but the presence of an output schema mitigates this. It could benefit from explicitly mentioning the baseline sensor (full frame 36mm) as a reference for calculation.

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 input schema already describes the single parameter (sensor_width_mm) with a minimum value and an example. The description adds no additional meaning beyond the schema, so with 100% schema coverage, a baseline score of 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 clearly states that the tool calculates camera crop factor and equivalent focal length based on sensor width. It uses a specific verb ('calculate') and identifies the resource, which is distinct among many similar 'calculate_' tools.

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 mentions 'See list_bundles for related 'photographie' calculators,' which provides some context but does not explicitly state when to use this tool versus alternatives, nor does it include when-not-to-use or prerequisites.

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