get_document_stats

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

Annotations are empty, so the description carries the full burden. It discloses what the tool returns (aggregates, breakdowns) but not behavioral traits like whether it is read-only, safe, or any side effects. For a statistics tool, this is a gap—it should state it's a read operation. The description implies no mutation but does not explicitly state it.

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 two sentences, front-loading the purpose and then giving usage guidance. Every word earns its place; no fluff or repetition. The Spanish is concise and clear.

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?

The description covers the return content well but omits scope context—does it return stats for the current user, a specific business, or all documents? Given siblings like get_user_info and list_businesses, the scope is ambiguous. Also, no mention of time period or filters. It's adequate for a no-parameter tool but leaves important contextual details unstated.

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 tool has zero parameters, so the schema provides complete coverage (100%). Per guidelines, a 0-param tool gets a baseline of 4. The description adds no parameter info because there are none, which 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?

The description clearly states the tool's purpose: aggregated statistics of tax documents, listing specific metrics (total issued, total invoiced amount, breakdown by DTE type, documents with error). It uses a specific verb ('obtener estadísticas') and resource ('documentos tributarios'), distinguishing it from list-oriented siblings like list_documents and get_document.

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 explicitly states when to use it: 'Usar cuando preguntan totales, resúmenes, cuánto han facturado o cuántos documentos emitieron.' This is clear trigger-based guidance. It does not mention when not to use it or name alternatives, but the context makes the intended use obvious.

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