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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds that it returns volume and weight, but with an output schema present this adds little beyond structured data, and no rate limits, auth, or density-handling behavior are disclosed.

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?

Short and front-loaded with the core computation first, then usage, inputs, returns, and routing. Every sentence is brief, though the inaccurate inputs sentence does not earn its place.

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 pure-calculation tool with full schema coverage, annotations, and an output schema, the description is largely adequate. The incomplete/misleading input list is the main gap, since the weight output presumably relies on a density default that is never explained.

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% and requires length_m, width_m, and depth_cm, but the description lists 'Inputs: area, depth, gravel density' - 'area' is a derived value and 'gravel density' is not a parameter at all. This mismatches the schema and could mislead the agent about what to supply.

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?

States a specific verb and resource: compute gravel volume (m³) and weight (tonnes) for a surface and depth. This clearly distinguishes it from generic volume tools like calculate_volume or calculate_compost_volume, though it doesn't explicitly name a sibling it is not.

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?

Gives use contexts ('paths, foundations, drainage') and routes to list_bundles for related construction calculators, which is helpful. However, there are no when-not conditions or explicit alternatives among the many sibling calculators.

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