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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered without the description. The description does add genuine behavioral context beyond that: only provinces *with* an agenda are returned, and the plans listed are the currently valid ('vigentes') ones. It says nothing about result size, ordering, pagination, or whether the value lists are static or change over time.

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 dense sentence with no filler, front-loaded on the primary content ('Las provincias con agenda'). The parenthetical is well used to qualify which plans are included. It is slightly over-compressed, stacking two distinct payloads (provinces+plans, and filter value lists) into one clause.

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?

There is no output schema, so the description must carry the return shape, and it only describes content, not structure — an agent cannot tell whether it receives a province→plans mapping, a flat list, or a single object with separate value arrays. For a no-parameter reference tool this is minor, but the shape ambiguity is the one remaining gap.

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 tool takes zero parameters, and the empty input schema is self-evident, so the baseline is 4. The description correctly adds that the returned date/temática/ocasión values are exactly the search domain for buscar_planes, which is meaningful semantics even without any input fields to document.

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 names the exact content returned: provinces that have an agenda (with their active plans) plus the temática, ocasión and fecha values accepted by buscar_planes. It is a noun-phrase specification rather than an explicit verb+resource statement, but the resource is unambiguous. It also distinguishes itself from buscar_planes by positioning itself as the source of that tool's valid filter values.

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?

By stating it returns 'los valores ... que acepta buscar_planes', it clearly implies this is the lookup to consult before calling buscar_planes with filters. That is a real when-to-use signal tied to a named sibling. It stops short of explicit exclusion rules or a full statement of when not to call it.

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