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

Annotations already cover read-only, idempotent, open-world and non-destructive behavior, so the description's added value is the operational constraints: no key required (no auth setup), a 10 MB size cap, and that the output includes data-range warnings. It does not mention failure modes for unreachable or non-EPW URLs, which is the main remaining gap.

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?

A single dense sentence that front-loads the purpose, then the returned values, then the access and size constraints. No filler, no repetition of the title or schema, and every clause carries information.

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 one-parameter, read-only fetch tool with an output schema already present, the definition covers purpose, accepted URL sources, auth requirements and a size ceiling. Only the exact URL format and error behavior are left unspecified, which is minor at this complexity.

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 0% and the single 'url' property is undocumented, so the description has to carry it. It does add meaning by naming acceptable sources (OneBuilding, EnergyPlus, a shared file) and the 10 MB limit, but it never says whether the URL must be a direct .epw file link versus a landing page or station ID.

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: 'Summary statistics of any public EPW by URL', and enumerates the returned quantities (location header, dry-bulb mean/min/max, GHI, warnings). This clearly separates it from the generate_* siblings, which create files rather than analyze one, though it never names a sibling explicitly.

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?

It gives usable context on acceptable inputs ('any public EPW by URL (OneBuilding, EnergyPlus, a shared file)') and notes the tool is free with no API key, which implies 'call this when you already have an EPW URL'. However, it never states when to prefer it over generate_epw or get_design_conditions, leaving the routing to inference.

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