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

Annotations already establish readOnlyHint=true, so safety is covered. The description still adds real value beyond that: it discloses pagination ('Paged'), the concrete field set returned, and the downstream dependency on billy_list_bank_lines. It omits auth requirements and rate limits, which keeps it below a 5.

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?

Two dense sentences with no filler, front-loading the resource and field list before the filtering hint and endpoint. The telegraphic phrasing ('Paged. GET /accounts.') is efficient, though the opening reads as a fragment rather than a clean statement of action.

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?

With no output schema, describing the returned fields is genuinely necessary and it is done well; pagination and read-only status are also covered. Nothing critical is missing for a simple filtered list call, though a note on the default paging behavior or auth would make it fully self-contained.

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 page, page_size and is_bank_account are already documented in the schema, making 3 the baseline. The description restates the is_bank_account semantics and adds the reason to use it, but supplies no syntax or format detail beyond the schema.

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?

It names the exact resource (the chart of accounts) and enumerates the returned fields (account number, name, group, nature, VAT rate, bank-account flag, IBAN/bank name), plus the underlying endpoint GET /accounts. It also distinguishes itself from the sibling billy_list_bank_lines by stating the relationship between them.

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 concrete selection condition (use is_bank_account=true to get the bank accounts whose ids billy_list_bank_lines needs), which routes the agent to a sibling correctly. It stops short of stating when not to use it or naming alternative list tools for non-account data, so it is clear context rather than full when/when-not guidance.

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