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

Beyond the readOnly/idempotent annotations, the description discloses the auth scope needed, the subscription-tier prerequisite, and the exact error contract (`plan_required` with `locked`) when the tier is insufficient. That is precisely the operational context annotations cannot carry.

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?

Two dense sentences: the first defines the resource and dimensions, the second covers prerequisites and failure behavior. No filler, and the core purpose is front-loaded.

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?

An output schema exists, so return values need not be described. With both params fully documented in the schema and the entitlement/error path spelled out, nothing an agent needs to call this correctly is missing.

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%, so the baseline is 3. The description adds the combinatorics the schema does not state: the filters are optional and may be used together ('por provincia y/o tipo de inmueble'), clarifying that neither is required.

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 concrete verb+resource: statistics on resolved auctions, enumerating the metrics (award rate, real discount, prices) and the breakdown dimensions (province and/or property type). It does not differentiate itself from plausible siblings such as `estadisticas_publicas`, `informe`, or `analisis_subasta`, which is the main gap.

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?

It gives entitlement context (requires an account with `informes:read` and a Pro plan or above) and the failure mode, which implies when the call will succeed. However, it never says when to pick this tool over `estadisticas_publicas` or `informe`, so the routing guidance is only implied.

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