describe

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds genuinely new context beyond that: resolution from the family's backing server, and that errors return a structured {'error': ...} payload instead of raising. It omits auth/rate-limit details, so 4 rather than 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?

Front-loaded with the core purpose, then labeled sections for usage and behavior. Every sentence carries information, though the 'When to use/When NOT to use/Behavior' scaffolding is slightly formulaic and longer than strictly necessary.

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?

An output schema exists, so return values need no explanation. For a single-parameter read tool, the description covers purpose, prerequisites, alternatives, error semantics, and idempotency — everything an agent needs to invoke it correctly.

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 coverage is 100% and the single parameter's description already documents the ISO 20022 format and the pain.001 resolution behavior with examples. The description adds no parameter-level 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 (describe) and resource (message type), and names the exact output (required fields and input JSON Schema). It is clearly distinguishable from siblings like 'search', 'validate', 'generate', and 'parse', which are referenced by name.

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?

Explicitly structures guidance with 'When to use' (after 'search', before 'validate'/'generate') and 'When NOT to use' (raw XML payloads → use 'parse' instead). Both the positive condition and the alternative are named, leaving nothing to inference.

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