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

Annotations already declare readOnly/openWorld=false/destructive=false, so the safety profile is covered. The description adds genuinely useful behavioral context: the output is a fixed-rule estimation and not an authoritative bank decision, plus a data-minimization statement (no name, DNI or contact data needed) that tells the agent what the tool will and won't consume.

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, front-loaded with what the tool returns before the estimation caveat and data-scope note. Every clause carries information, though the second sentence packs several ideas (estimation nature, input scope, privacy) that could be separated for easier scanning.

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 carries the burden of describing return values, and it does so well (score, letter, per-category semaphore, strengths/weaknesses/alerts). Combined with the input-scope note, an agent has enough to call it correctly, with the only shortfall being partial parameter explanation against a 55% schema coverage and multiple required fields.

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 55%, so the schema documents only part of the 11 parameters. The description partly compensates by naming the categories derived from inputs and clarifying the data scope, but it does not explain required fields such as consentimiento_informado, plazo_anos or the titulares structure beyond what the schema already conveys. Baseline 3 is appropriate for this mid-level coverage.

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 deliverable: a 0–100 score plus an A–E letter for a given operation, broken down by category (effort, financing, job stability, savings, age at maturity) with strengths, weaknesses and alerts. That is a concrete verb+resource an agent can recognize. It does not, however, distinguish itself from close siblings like mortgage_evaluar_viabilidad or mortgage_calcular_capacidad.

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 frames the tool as a prior estimate with fixed rules, 'not a bank's study,' which implicitly positions it before a real lender assessment (mortgage_solicitar_estudio), and it notes it only needs operation and holder economic data. But it never explicitly says when to prefer this over the other mortgage siblings or names an alternative, leaving the routing to inference.

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