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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's main added value is disclosing the return payload: calculated value with units, method/formula, derating or correction factors, and governing code reference. The '[PRO]' prefix signals a paid/authenticated tier, though the description never states that an api_key parameter is required or what happens without it.

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?

Purpose and the when-to-use clause are front-loaded, then return behavior, then capability list, then examples — a logical progression with no filler. The 'and more' capability sentence and the long example list are slightly padded but each still carries routing value.

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 correctly compensates by describing the return contents. It covers trades, units, and jurisdictions, but omits the Pro API key prerequisite that the schema reveals — a material gap for an agent that would otherwise fail the call.

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%, so the baseline is 3; the description earns above that by giving three concrete example inputs that model how to populate the free-text 'calculation' parameter. It does not add anything about 'role' or 'region' beyond the schema, which keeps it from a 5.

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 ('performs numerical technical calculations') plus the domain (construction trades) and explicitly separates itself from the nearest sibling by saying 'not just checked for compliance', which points at check_compliance. An agent can distinguish it from all seven siblings without opening a schema.

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?

'Use this tool when a specific measurement, size, rating, or capacity needs to be calculated — not just checked for compliance' gives an explicit when-to-use plus an implicit exclusion routing compliance checks elsewhere. The enumerated capability list and three worked example inputs further anchor invocation.

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