beel_get_invoice_pdf

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

The description discloses expiration (five minutes), HTTP method restriction (only GET), polling semantics (202 until 200), and specific error codes (400 INVOICE_NOT_ISSUED_NO_PDF). It also details security behavior around NIF existence disclosure in the parameter description, going well beyond the readOnly/idempotent hints in annotations.

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?

Three short paragraphs, each serving a distinct purpose: return value, polling behavior, and error handling. No fluff, front-loaded with the primary function, and every sentence earns its 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 no output schema, the description covers all necessary aspects: URL behavior, expiration, polling decisions, error conditions, and the alternative for drafts. Combined with the annotations, it is fully actionable with no missing critical information.

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 100%, so the baseline is 3. The tool description itself adds no parameter semantics beyond what the schema already provides, though the schema's company_id description is exceptionally detailed. No additional value from the description itself.

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 (Returns) and resource (temporary pre-signed URL for invoice PDF), and clearly differentiates from the preview endpoint by naming it as an alternative. The endpoint path is included for precise identification, making the tool's purpose unmistakable.

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 explains when to poll (202), when to expect 400 for drafts, and points to the preview endpoint as the alternative for drafts. This gives an agent clear decision guidance on when to use this tool vs. the preview, exceeding mere context.

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