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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety bar is lower; the description still adds real value by declaring the function pure/stateless with no floating-point drift and by enumerating the structuredContent fields returned. It stops short of describing preconditions (e.g. what inputs produce an error versus an ok=false reconciliation).

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?

Front-loaded with purpose and the arithmetic guarantee before the field enumeration; every sentence is informational. The long parenthetical list of return fields and modes is dense but earns its place given there is no output schema.

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 stateless, read-only calculator with a fully documented 8-param schema, a complete annotation set, and no output schema, the description covers purpose, usage routing, computational semantics, and the shape of the response. An agent has everything needed to invoke it correctly and interpret the result envelope.

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%, with every parameter documented including ranges, defaults, and the singular/plural credit-note alias, so the schema carries the load. The description only reinforces the unit convention (integer cents, no floats) and adds no syntax or interaction rules beyond it. 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?

Opens with a specific verb+resource: reconcile B2B wholesale Net-15/30/60 invoice deposits, partial payments, and credit notes, and adds the distinguishing trait of exact integer minor-unit arithmetic. It explicitly separates itself from the VAT sibling, so an agent can tell the two apart without opening schemas.

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?

States the intended use case ('B2B wholesale order deposit gating and Net-terms balance calculation') and routes the agent away to revclamp_validate_eu_vat_vies for VAT validation. It does not address the other seven siblings (disputes, ROI, ghost usage, webhooks), so the exclusion guidance is partial rather than complete.

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