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

Annotations declare readOnlyHint=true and openWorldHint=false, so the agent knows it is a pure, deterministic computation. The description adds the exact formulas and the IRC 7¾ in check, which are behavioral details beyond the annotations. It does not disclose limitations (e.g., uniform riser assumption) or output format, hence not a 5.

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: the first front-loads the outputs, the second supplies the formula. No filler; every clause serves a purpose. Dense but appropriate for a calculator.

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 3-parameter calculator with no output schema, the description enumerates the four outputs and the formula, giving the agent enough to understand the return values. It does not specify output units or precision, and doesn't state the return structure, so a small gap remains.

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 each parameter has a description with default values. The description adds value by linking the parameters in explicit formulas (e.g., riser height = total rise ÷ risers; stringer length = √(rise² + run²)), clarifying how they interact. This goes beyond the per-parameter schema descriptions.

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 exactly what the tool computes: number of risers and treads, riser height, total run, and stringer length, from floor-to-floor rise, with an IRC check. The resource (stair stringer) is unique among siblings, so the agent can distinguish it immediately.

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?

No explicit when-to-use or alternatives are given. The formula and IRC check imply the context (building code-compliant stair design), but the description does not say when to choose this over manual calculation or other calculators.

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