Validate ISO 20022 MX message

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

With no annotations, the description carries the full burden. It discloses the specific validation checks, the limitation of not being an XSD validator, and the CBPR+ 2026 rule. However, it does not describe the return format (e.g., list of issues vs pass/fail) or any other operational behavior, leaving a minor transparency gap.

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?

Two sentences, front-loaded with the core purpose, then a concise list of checks, and a valuable caveat. No filler or redundancy; every word earns its 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?

The description thoroughly covers the tool's scope, exceptions, and practical usage context, which is strong for a 2-parameter validator. However, since there is no output schema, it would be more complete if it hinted at the return type (e.g., list of errors, boolean). This minor omission prevents a perfect score.

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%—both message_type and xml have descriptive schema entries. The description adds no new parameter-level details beyond restating the message types (pacs.008, pacs.009) already present in the enum. It meets the baseline for full schema coverage but does not elevate it.

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 clearly states the tool validates ISO 20022 MX messages (pacs.008 or pacs.009) and lists specific structural issues checked, distinguishing it from sibling MT validation tools. It uses a specific verb ('validates') and resource ('ISO 20022 MX message'), and the scope is unambiguous.

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 says 'Not a full XSD validator — use for a fast pre-check before schema validation', providing both a when-to-use and a when-not-to-use. The focus on MX vs MT and the listed checks give clear context for when this tool is appropriate relative to siblings.

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