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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false), the description discloses high-value behavior: the call is free, does not consume the free allowance, still works after the allowance is spent, and is read by a human. The quota interaction is exactly the kind of context an agent cannot infer from structured fields.

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, then usage conditions, then the quota-exemption note — a sensible order with little waste. The capitalized 'PAYING' and the parenthetical blocker list are slightly emphatic but carry real information about accepted report types.

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?

Seven parameters with full schema coverage plus an output schema mean the description needn't explain fields or returns; it concentrates on when to call and the allowance exemption, which is what an agent cannot get elsewhere. Nothing needed to invoke correctly is missing.

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 every field including the error_type enum. The description's category list loosely mirrors that enum, but it adds no syntax, format, or bundling guidance beyond the schema, so the baseline 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 and target: 'Report a problem or a need directly to the IBANforge operators', then enumerates the exact report categories (wrong validation, stale BIC, latency, blockers). An agent can immediately distinguish this from sibling validation/lookup tools.

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?

The explicit 'USE WHEN' clause gives concrete triggering conditions (wrong result, missing data, hitting a wall on quota/payment/capability). It does not name alternatives such as validate_iban or lookup_bic as the tools to use instead for normal work, so it stops short of full when-not guidance.

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