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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds data range (2000–2025) and technology category coverage, which is useful context beyond annotations. It does not describe response format or pagination, but given the annotations carry the safety burden, a 3 is appropriate.

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?

Three sentences, front-loaded with the core purpose, then scope details, then use cases. No redundant wording or filler. It is appropriately sized for a moderately complex tool with 5 parameters.

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 value documentation is covered. The description explains the data scope, units, time range, and typical applications, which is sufficient for an agent to decide when to invoke it. It does not mention parameter defaults, but the schema provides those.

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 100%, so the baseline is 3. The description adds unit (MW) and source database (IRENASTAT), but otherwise largely repeats the enum values for regions and technologies. It also claims '13 technology categories' while the schema lists 12, a minor inconsistency that doesn't significantly impair understanding.

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 a specific verb ('Query'), a specific resource ('renewable and non-renewable electricity installed capacity in MW'), and a distinct aggregation level ('by IRENA world region'). It explicitly lists the regions and time range, clearly differentiating it from sibling tools like capacity_country or generation_country by the aggregation dimension.

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?

Provides clear use cases ('comparing regional energy transition progress', 'identifying leading regions in solar/wind deployment', 'tracking global renewable capacity milestones') that tell an agent when this tool is appropriate. However, it does not explicitly name alternative tools or state when not to use this tool, so it falls short of the highest bar.

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