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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds real value beyond that by disclosing pagination semantics ('pages of up to 500') and the response envelope (items, total, offset, limit), which matters because there is no output schema.

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 and the three-beat structure (what it lists, what a record holds, how to filter, how it pages) is logical. The second sentence is a long dense enumeration, but since there is no output schema those field details earn their place.

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, the description compensates by describing record fields and the pagination envelope, and all ten parameters are documented in the schema. The only gap is that it does not address the multi-organisation requirement beyond the schema, but overall it is sufficient for correct invocation.

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 the schema already documents all ten parameters in detail, including the tax_year convention and expense_type enum values. The description only restates the filterable dimensions at a high level and adds no syntax or format detail beyond the schema, so the baseline 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 ('Lists') and resource ('expense records') and then enumerates what each record contains (date, due date, supplier, type, account, amount in NZD, property, liable people), which is genuinely informative. It does not, however, differentiate itself from the singular sibling get_expense_record or from list_income, so an agent gets no explicit routing hint.

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?

'Filter by tax year, type, account, contact, property or dates' implies when the tool is useful, but there is no explicit when-to-use/when-not statement and no alternative tool is named. Usage must be inferred from the available filters rather than stated.

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