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

No annotations are provided, so the description must fully disclose behavior. It merely states the calculation without mentioning side effects, prerequisites, or limitations (e.g., that it is read-only). The description does not contradict any annotations (none exist), but it fails to add behavioral context beyond the obvious.

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 extremely concise: two sentences that front-load the purpose and provide a sibling reference. Every word earns its place, with no redundancy or filler.

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 the tool's simplicity and the presence of an output schema (as indicated by context signals), the description covers the core functionality and return values. It references a parent context ('list_bundles') for related tools. However, it could briefly mention the underlying exposure triangle relationship for completeness.

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 coverage is 100%, with each parameter already described (e.g., 'ISO sensitivity value'). The description adds no new meaning beyond naming the parameters in the first sentence. It does not clarify relationships or provide usage details beyond what the schema offers.

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 the tool calculates the missing exposure value (aperture, shutter speed, or ISO) given the other two. It specifies the return object with ev_value, lv_value, and shutter_speed_s. The mention of 'list_bundles' for related calculators adds context, though it does not explicitly differentiate from sibling photography calculators like 'calculate_depth_of_field'.

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 two of the three exposure parameters are known, but it offers no guidance on when to prefer this tool over alternatives (e.g., other photography calculators). The reference to 'list_bundles' hints at related tools but does not provide explicit exclusions or use cases.

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