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

Annotations provide no safety profile (all hints false), so the description carries the burden. It adds useful behavioral context: each line carries debit/credit/bank_ref, the response includes totals, and filtered totals are explicitly warned not to balance. However, it does not disclose the response format, pagination behavior, or side effects, and the ambiguous 'Free.' adds little clarity.

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 concise and front-loaded with the verb and resource, packing filters and return-field information into two dense sentences. The final standalone sentence 'Free.' is cryptic and does not earn its place, preventing a perfect score.

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 9-parameter tool with no output schema and no annotations, the description covers the core listing behavior and main return values. It leaves gaps: no statement about response structure or pagination, no clarification of how required from/to relate to optional since/until, and no caveats about limit or currency beyond what the schema already states.

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?

The input schema already documents all 9 parameters with descriptions and constraints, so schema coverage is 100% and the baseline is 3. The description only groups parameters into categories (account, source server, source_id, date) and adds no syntax, formatting, or semantic detail beyond what the schema already provides.

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 opens with the specific verb 'List' and resource 'ledger lines', and enumerates filter dimensions (account, source server, source_id, date) and returned fields (debit, credit, bank_ref, totals). It is clear and detailed, but it never explicitly distinguishes itself from sibling tools like ledger_report or ledger_export_csv.

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?

There is no guidance on when to use this tool versus alternatives such as ledger_report, ledger_export_csv, or trial_balance. The use case is only implied by the verb and filter list; no alternatives or exclusion conditions are mentioned.

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