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

The description depicts a pure read/listing operation, yet the annotations declare readOnlyHint=false, which is inconsistent and could make an agent hesitate or expect side effects; the description does nothing to reconcile this. It does add useful behavioral detail beyond the annotations — deterministic newest-first ordering, the fact that totals are NEGATIVE, and per-currency aggregation — but omits result-size/pagination 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?

One front-loaded sentence covering purpose, return shape and filtering, with zero filler. It is dense — the return-field list and the filter list are packed together — but nothing is redundant.

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?

There is no output schema, so describing the returned fields, ordering, and the negative-total convention is genuinely necessary and well done. Missing: any indication of pagination, limits, or default result size for an unfiltered list, which matters for a 0-required-parameter listing tool.

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 format hints (YYYY-MM-DD) and substring semantics for client, so the description only restates the filters. It adds no syntax or combination rules beyond what the schema already documents, making the baseline 3 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 and resource ('List credit notes') and enumerates exactly what each row contains (id, invoice, client, basis, reason, currency, negative total, credited amount per currency). This clearly separates it from siblings like credit_note_get, credit_note_text and credit_note_pdf, which return a single note or a rendered 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?

It gives a clear usage context: browse all notes newest-first, or narrow by invoice, client, or issue-date range. It does not explicitly name alternatives (e.g., 'use credit_note_get for a single note by id'), so the agent must infer routing from the sibling names.

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