beel_list_stats

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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses significant non-obvious behavior: the exclusion of drafts/proformas, the separate counting of rectifying invoices, the conditional counting of voided invoices, and the non-monotonicity that makes it unsuitable as a cursor. This is valuable context that annotations cannot convey.

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 tight paragraphs: the first front-loads the core purpose and counting rules, the second explains the non-monotonic caveat and gives the endpoint. Every sentence earns its place; no filler or redundancy.

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 there is no output schema, the description explains the key semantics (count, last_invoice_at, exclusions) and the endpoint. However, it does not describe the response structure (e.g., array of objects with NIF, count, and last_invoice_at fields) or pagination behavior. This is a minor gap since the core information needed for correct usage is present.

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%, and the schema itself already provides a detailed explanation of account_id (including authorization scope and error semantics). The tool description adds nothing about parameters, so the baseline 3 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 states a specific verb ('Returns') and resource ('for each company (NIF) of the account, how many fiscal documents it has issued and when it last issued one'), and clarifies exclusions (drafts, scheduled invoices, proformas). It distinguishes itself from siblings like beel_list_invoices and beel_get_fiscal_summary by focusing on per-company document counts, making its 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?

The description provides a usage caveat (not usable as a synchronization cursor due to non-monotonic count) and explains the counting rules, but it does not explicitly state when to prefer this tool over alternatives or when not to use it. No sibling tools are named as alternatives, so the guidance is implied rather than explicit.

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