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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so no contradiction. The description adds valuable context: it returns a bundled multi-part history, includes current sanction status, and excludes RUC 10 entities. However, it doesn't disclose auth needs, rate limits, or whether the response is paginated, which would fully earn a 5.

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 sentences: the first lists all returned data items, the second clarifies the exclusion. It is front-loaded and efficient, though the enumerated list could be slightly more scannable. Zero wasted words.

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?

Given a simple, read-only, single-parameter tool with no output schema, the description is complete: it tells the agent exactly what data comes back, outlines scope, and notes the key limitation (RUC 10 exclusion). Nothing critical for correct invocation 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?

The schema description already documents the single parameter (RUC de 11 dígitos que empieza en 20) with 100% coverage. The description reinforces the 'RUC 20' constraint but adds no additional syntax or format details beyond what is already in the schema. Baseline 3 is appropriate.

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 ('Devuelve') and resource ('historial público con el Estado peruano de una empresa con RUC 20'), then enumerates exactly what data is returned. The exclusion of RUC 10 (personas naturales) differentiates it from sibling tools. An agent can tell at a glance which tools this replaces or complements.

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?

The description clearly implies usage for querying public procurement history of a company with RUC starting with 20, and explicitly rules out RUC 10. It does not name which sibling tools (e.g., verificar_sancion, buenas_pro) to use for specific subtasks, so it's not a 5, but the scope is clear enough to avoid misinvocation.

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