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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds one genuinely valuable fact not in structured data: the call costs 3 credits. It does not disclose that this is asynchronous work requiring polling via get_job_result, nor what happens to an existing EPW at the same path.

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 dense fragment-sentences with the verb and cost front-loaded and zero filler; every clause carries information. The telegraphic style is efficient but borderline cryptic, and the parameter hints are jammed into one run-on line rather than structured per argument.

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?

An output schema exists, so return values need not be described. Still, for an 8-parameter, credit-consuming, asynchronous generation tool, the description omits the async/job-result workflow and leaves base_year and location_name undefined, which is not enough to call it confidently on the first try.

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?

With 0% schema description coverage and no enums, the description must carry the weight and does partially: it enumerates the four valid scenario strings and constrains horizon to decades 2030-2100. But half the parameters remain uninterpreted, most importantly base_year (the morphing reference period, default 2010) and location_name, whose purpose and effect are not explained anywhere.

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 artifact: 'Start a CMIP6-morphed future EPW' with the Belcher 2005 method named. This clearly separates it from generate_epw (present-day), generate_tmy (typical year) and generate_forecast. It loses a point only because 'EPW', 'CMIP6' and 'morphing' are unexplained jargon that an unfamiliar agent must infer.

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?

Implicitly scopes the tool to future-climate scenario files and explicitly routes the agent to list_cmip6_models for the model argument, which is genuinely useful. However, it never states when to prefer this over generate_epw or generate_forecast, nor any prerequisites such as needing a valid api_key with credits available.

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