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 real value annotations cannot: which fields are conditional ("cuando existen"), the provenance of certain data (RNIE, ComprasMX, PROFEPA, DENUE), and that the record is public — telling the agent to expect absent or partial fields rather than errors.

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?

Purpose is front-loaded in the first clause and the input requirement in the last, with no filler sentences. The middle field enumeration is long and runs on as a single sentence, but with no output schema each listed field earns its place.

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?

With no output schema, the description carries the return-value burden and does so thoroughly, listing the fields and flagging which are conditional. The single input is fully accounted for; only edge cases (invalid or stale id/URL, behavior when the company has no enriched data at all) are left implicit.

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% and the single parameter's description already specifies the 'directorio:slug' format and the URL alternative. The description restates that same duality and only adds the explicit link to buscar_empresas, so it is essentially at baseline with no extra syntax or format detail.

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 ("Devuelve la ficha pública completa de una empresa") and then enumerates the exact fields returned, including conditional ones marked "cuando existen" (RNIE, ComprasMX, PROFEPA). It also names the sibling that produces its input (buscar_empresas), so an agent can place it in the workflow without opening the schema.

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?

Clearly establishes the entry condition: the id must come from buscar_empresas or be a ficha URL, which implies a search-then-view flow. It never states when NOT to use it or points to alternatives such as ver_sucursales for branch-only data, so guidance is clear but not exclusionary.

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