listar_unidades

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

Although no annotations are present, the description implies a safe, read-only operation by describing a list retrieval. It adds value by detailing the return structure, which goes beyond the empty input schema. However, it does not explicitly state that the operation is non-destructive, but for a 0-parameter list tool, this is sufficient.

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?

The description is extremely concise: one sentence for purpose and a bullet-point structure for the return value. It is front-loaded and every part is essential, with no wasted words.

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?

Given the tool's simplicity (no parameters, no annotations, and a clear return structure described), the description is complete. It tells the agent exactly what the tool does and what to expect as output, which is all that is needed for selection and invocation.

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 zero parameters and 100% schema coverage, the baseline is 4. The description does not need to add parameter details as there are none, and it correctly omits any irrelevant information.

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 clearly states the tool lists all supported units for a unit converter, specifying the return structure with weight and area lists. It distinguishes itself from sibling tools like 'converter' which likely performs the actual conversion.

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?

No guidance is provided on when to use this tool versus alternatives. It is implied that it should be used before converting units, but this is not explicitly stated, leaving the agent without clear usage context.

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