beel_get_invoice

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive. The description adds the endpoint and fiscal guardrails link but doesn't specify return format or error behaviors beyond what the schema covers. The guardrails mention when an invoice can be changed, but that's more about the invoice lifecycle, not this tool's 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?

Concise and front-loaded. Two sentences plus a callout and pointer. No fluff. The endpoint and guardrails earn their 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?

For a read-only retrieval tool with annotations covering safety, the description is mostly complete. It points to docs for exhaustive rules. However, the phrase 'full details' is vague; with no output schema, a note on what fields are returned would improve completeness.

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%, with company_id having an extensive description. The tool description adds no parameter details beyond the schema. Baseline 3 applies since schema carries the semantic weight.

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?

Description states a clear action ('Retrieves the full details of an invoice') and specifies the resource scope ('of this company (NIF)'). It is distinct from list and PDF tools though it doesn't name alternatives, so it lacks explicit sibling differentiation but is still specific.

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?

No explicit guidance on when to use this tool vs alternatives like beel_list_invoices or beel_get_invoice_pdf. The fiscal guardrails note is about invoice modification rules, not tool selection. It points to docs but doesn't clarify usage context.

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