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

Annotations already declare readOnly/idempotent/non-openWorld, so the safety bar is low. The description adds genuinely useful behavior: the similarity inputs (price, rent, minutes to Barcelona, size, property tax), the geographic constraint (50 km or same county), that the method is returned with the answer, and the 'not a recommendation' caveat.

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?

Front-loaded with the core output before the methodology caveats, and every clause carries information. The bilingual duplication doubles the length, but that is deliberate for the target user base rather than padding.

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, and the description compensates well by enumerating the returned fields (similarity index, €/m², distance) and explaining the computation and geographic limits. An agent has enough to call and interpret the tool, though edge-case guidance when fewer than five matches exist is absent.

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 coverage is 100% with only two well-documented parameters, so the schema does the heavy lifting. The description confirms the 'given municipality' input conceptually but adds no syntax, format, or slug guidance beyond what the schema already provides.

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 and resource ('five municipalities most similar to a given one') plus the secondary cheaper-variant output, distinguishing it clearly from siblings like comparar_municipios or buscar_por_presupuesto. The scope, output fields and computation basis are all named up front.

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?

Usage is implied by the description – you use this when you want alternatives to a given municipality – and 'Not a recommendation' sets a boundary on how the result should be treated. However, it never explicitly says when to prefer this over comparar_municipios or buscar_municipios, so routing is left to inference.

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