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

Annotations set readOnlyHint=true, consistent with a calculation tool. Description and annotations align: no destructive actions, output is computed values. Description discloses returned fields (hyperfocal distance, near/far limits, bokeh classification) beyond 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 sentences, no redundant information. First sentence states operation and outputs; second sentence gives usage context. Efficient and to the point.

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?

No output schema, but description lists returned values (hyperfocal distance, near/far limits, bokeh classification). Parameter count (4) and schema coverage are adequate. For a calculation tool, the description sufficiently informs the agent about inputs and outputs. Minor gap: no explicit indication of result format or units, but they are implied.

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% with clear parameter descriptions (e.g., sensor enum explained). The tool description adds context by listing parameters in the first sentence but does not enhance understanding beyond what the schema already provides. Baseline 3 for high coverage.

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?

Description clearly states the tool calculates depth of field for given focal length, aperture, distance, and sensor type, specifying outputs (hyperfocal distance, near/far limits, bokeh classification). It uniquely distinguishes from sibling 'calcular' tools which cover different domains (fitness, cooking, etc.).

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?

Description provides practical use cases: determining background blur or aperture for landscapes. It implies when to use but does not explicitly mention when not to use or list alternatives. Given distinct sibling tools, no alternatives needed, but slight lack of exclusion criteria.

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