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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safe-read profile is fully covered without prose. The description's note that it returns labels and IDs is largely redundant with the existing output schema, so it adds little behavioral context beyond what structured fields provide.

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 front-loaded sentence covering purpose, examples, and output use with zero filler. Every clause earns its place.

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 rich annotations and an output schema present, most behavioral and return-value burden is offloaded to structured fields. The only real gap is the undocumented 'limit' parameter, which slightly undermines completeness for an agent that wants to control result volume.

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 single parameter 'limit' has 0% schema description coverage, so the description must compensate — but it never mentions the parameter or its role in result-set size. The agent is left guessing whether the parameter is required or what it controls.

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 (List) and resource (dataset themes/categories) scoped to datos.gob.es, with concrete examples (Economy, Health, Transport). It also implicitly separates itself from the broader 'datasets' sibling by positioning itself as a filter source, though it doesn't name the sibling as an explicit alternative.

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?

Explains the intended downstream use of the output — as a filter in the datasets tool — which tells the agent when this tool is the right first step. It stops short of explicit when-not-to-use guidance or naming a sibling alternative directly.

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