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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds the returned field names, but with an output schema present that is largely redundant; it discloses nothing further about constraints or edge cases (e.g. the slope 0-80 range implication).

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 short sentences, front-loaded with the operation, with no padding. The return-value enumeration is somewhat redundant given the output schema, a minor inefficiency rather than bloat.

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 3-parameter read-only calculator with an output schema and full annotation coverage, the essentials are present. The only real gap is guidance on choosing this calculator over the nearby roof/area siblings.

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 all three parameters documented (base_length_m, base_width_m, slope_degrees). The description only restates 'building footprint and slope angle' and adds no unit, range, or format nuance beyond the schema, so the baseline 3 applies.

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 ('Calculate roof surface area') and names the inputs (building footprint and slope angle), so the operation is unambiguous. It does not, however, differentiate itself from the close sibling calculate_roof_truss beyond a generic pointer to list_bundles, keeping it just shy of a 5.

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?

There is no statement of when to use this tool versus alternatives such as calculate_roof_truss, calculate_floor_area, or calculate_area. The only routing hint is a generic 'See list_bundles for related construction calculators,' which defers the decision rather than informing it.

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