beel_get_invoice

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds the HTTP endpoint and the dependency on fiscal rules / the invoice state machine, but says nothing about what 'full details' actually returns, pagination, or error behavior (e.g. 404 for missing invoice).

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?

Purpose is front-loaded in one sentence, followed by the endpoint and a clearly marked warning block. The warning block is slightly malformed — 'The status names, the proforma lifecycle, and which tool performs each operation.' is a dangling fragment — but overall it is compact and skimmable.

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 tool with full annotation coverage and 100% schema coverage, the description supplies the purpose, the endpoint, and the required prerequisite resources. The main gap is that with no output schema, 'full details' is never unpacked, but an agent has enough 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 description coverage is 100%, so both company_id and invoice_id are already documented in the schema, including the 403/context semantics for company_id. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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 and resource ('Retrieves the full details of an invoice') and pins it with the exact endpoint GET /v1/companies/{company_id}/invoices/{invoice_id}, which clearly separates it from list/aggregate siblings. It does not, however, explicitly name or contrast itself with close siblings like beel_get_invoice_pdf, beel_get_invoice_preview, or beel_list_invoices.

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 '⚠️ Read before calling' block gives preconditions — consult beel_rules_list and the beel://guardrails/invoice-state-machine resource — which is real usage context. But it never says when to choose this tool over the several invoice-reading siblings, and the guidance is framed as documentation pointers rather than selection criteria.

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