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

There are no annotations, so the description carries the behavioral burden; it discloses that missing inputs fall back to documented defaults and that the tool produces calculated quantities rather than performing an enquiry/submission. It does not explicitly state 'no side effects,' but a pure calculator's read-only nature is strongly implied by the output-oriented wording.

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 one tight sentence with the action front-loaded and no filler beyond the redundant 'calculator calculator'. The semicolon-separated output list is compact and each item adds information. Minor word duplication prevents a 5.

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?

With no output schema, the description usefully enumerates four outputs (actual roof area, squares, panel area to order, installed rate used) and the default-fallback behavior. It is complete enough to invoke the tool with confidence, though it doesn't define the exact response structure or an explicit total-cost figure, which would be helpful for a 'cost calculator.'

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?

The input schema already documents all 7 parameters with defaults and descriptions (100% coverage), which sets the baseline at 3. The description adds only the global fallback behavior and output names like 'Panel area to order, including waste' that slightly enrich waste semantics, but it does not compensate for or add much beyond the schema.

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 names the exact action ('Run') and resource ('Metal roof cost calculator') and lists the computed outputs, so an agent can tell this is the calculation tool. It does not explicitly contrast it with calculator_describe or submit_enquiry, but the verb and output list are clear. The duplicated 'calculator calculator' is awkward but not confusing.

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 use case is implied by the title and the imperative 'Run'—this is the tool for computing metal-roof values, not for describing or enquiring. However, the description never states when to prefer it over the sibling tools or gives exclusions/prerequisites. The fallback-default note is an invocation rule, not usage routing guidance.

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