sumar

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

With no annotations, the description carries the burden. It clearly states the core behavior: adds two numbers and returns the result. The absence of side effects is implicit in a pure arithmetic operation. Minor details like return type or error handling are not specified, but for such a simple tool this is acceptable.

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 a single, front-loaded sentence that expresses the operation and result with no wasted words. Every part of the sentence adds value.

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?

The tool is trivial, parameters are fully described in the schema, and the description covers the return behavior at a basic level. There is no output schema, but stating that the result is returned is sufficient for a two-number addition. It could have specified that the result is a number, but that is obvious.

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 both parameters are already documented in the input schema ('Primer número a sumar' and 'Segundo número a sumar'). The tool description adds no additional meaning about how 'a' and 'b' are used, so the baseline of 3 applies.

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 uses a specific verb ('suma') and resource ('dos números'), and states the outcome ('devuelve el resultado'), so an agent knows exactly what the tool does. It naturally distinguishes from the sibling 'saludar', which is a completely different domain.

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?

The behavior implies use whenever two numbers need to be added, and the sibling tool is unrelated, but the description does not explicitly state when to use it or provide exclusion criteria. No alternatives are mentioned, so the guidance is implied rather than explicit.

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