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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds only the vague temporal notion of 'proximos' and says nothing about ordering, date range, what happens when limit truncates results, or how city filtering behaves. It does not contradict the annotations, but it adds little behavioral context beyond them.

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 with no wasted words. Its brevity is appropriate for a simple list tool, though it may be too sparse given the sibling ambiguity and undocumented limit behavior.

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?

For a simple read-only, two-parameter listing tool with annotations and no output schema, the description is minimally adequate. However, it leaves important context implicit: what 'proximos' means in practice, whether results are sorted, and how the limit default of 5 affects completeness. An agent could call it, but not with full confidence about the returned scope.

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 50%: the 'city' parameter has only the tautological schema text 'Ciudad opcional,' and 'limit' has no description at all, only numeric constraints. The tool description merely repeats that city is optional and does not compensate for the undocumented 'limit' parameter or explain how filtering interacts with results.

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 and resource: 'Lista los proximos eventos VITUR,' plus an optional city filter. It is clear what the tool does, but it does not explicitly differentiate itself from the singular sibling 'vitur-proximo-evento' or from search-oriented siblings like 'vitur-buscar-eventos'.

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 description gives no guidance on when to use this tool versus alternatives such as 'vitur-proximo-evento' (singular) or 'vitur-buscar-eventos'. The only hint is the word 'proximos,' which implies upcoming events but does not define the boundary or exclusions.

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