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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is known. The description adds the behavioral detail of bulk execution ('accepts ids for batched execution'), which is not in annotations. It does not contradict annotations and provides useful extra context about how the tool can be invoked.

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?

The description is extremely concise: two sentences, immediately stating the purpose and a key additional capability. There is no filler or repetition. Every word earns its place, making it easy to parse.

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 the tool is a simple GET-by-id with good annotations (readOnly, idempotent, non-destructive), the description covers the core usage and even adds bulk support. No output schema is present, so return format is not specified, but for a simple view it may be acceptable. It does not mention authentication or prerequisites, but those might be implied by the broader API context. Overall it's reasonably complete for its complexity.

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 description coverage is 0%, so the description must compensate. It explains 'id' implicitly via the endpoint and mentions 'ids' for bulk support, but leaves 'query' and 'account' entirely unexplained. This is a significant gap since these parameters could have important semantics. The description partially adds meaning but does not cover all parameters.

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 clearly states the tool retrieves a purchase ('Compras: Visualizar') and specifies the exact endpoint (GET /api/compras/{id}). It distinguishes from siblings like compras_list by indicating it's for a single resource, and the bulk support note adds specificity. The verb 'Visualizar' and resource are unambiguous.

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 implies this tool is for viewing a specific compra by id, and the bulk support note hints at using it when needing multiple specific ids. However, it does not explicitly mention when to prefer this over list or other alternatives, nor does it state any exclusions. It's clear enough but lacks explicit guidance.

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