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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description still adds value by clarifying the absence of side effects (no skill installation, no file download) and describing the guide's internal structure, though it says nothing about size, latency or error behavior.

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, both front-loaded with the essential information (what it reads, then the id rule and the non-effects). No filler or restatement of the title.

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 rich annotations, a full output schema and 100% parameter coverage, the remaining burden on the description is small, and it covers purpose, id provenance and scope exclusions. An agent has everything needed to call it correctly.

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, but the description adds a meaningful constraint beyond the schema: the id must be a guide id, not a resource id. The response_format parameter is left entirely to the schema, which is acceptable given its full description and enum.

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?

Specific verb+resource ('Lee una guía completa') plus an enumeration of content (pasos, ejercicio, criterios de revisión, referencias atribuidas) that tells an agent exactly what it gets back. It also draws the sibling boundary by naming buscar_skills as the source of the id.

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?

Explicitly states the precondition ('Usa un id de guides devuelto por buscar_skills, no el id de un recurso') and a scope exclusion ('No instala skills ni descarga archivos'). It does not say when to prefer this over preparar_proyecto or the vektro tools, so it stops short of full when/when-not/alternatives guidance.

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