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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds a brief return-object summary, but since an output schema exists and no computation assumptions, permissions, or edge cases are disclosed, it provides limited additional behavioral context.

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 two compact sentences, front-loads the core purpose, then adds return fields and a cross-reference. Every sentence earns its place with no unnecessary detail.

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 low-complexity calculator with full schema coverage, annotations, and an output schema, the description is nearly sufficient. It states what is computed and points to related bundles, though it omits guidance on when to prefer this over the dedicated hyperfocal-distance 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%, so the schema already documents all four parameters including units and defaults. The description adds no extra parameter meaning, such as how sensor_width_mm affects results or acceptable ranges beyond what the schema states, so the baseline 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 states a specific verb and resource: it calculates depth of field, near/far focus limits, and hyperfocal distance for a camera lens. This is clear and scoped, but it does not explicitly differentiate itself from the sibling tool calculate_hyperfocal_distance, which is a closely related calculator.

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 only usage guidance is 'See list_bundles for related photographie calculators,' which points to related tools but does not state when to use this tool versus alternatives like calculate_hyperfocal_distance. Usage is implied by the purpose statement, but no explicit when/when-not guidance or exclusions are provided.

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