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

With no annotations provided, the description has to carry the behavioral load. It does disclose two useful traits: automatic message-type detection and structured JSON output. However it says nothing about error/failure behavior, whether parsing is side-effect free, permission needs, or what 'structural checks' in validate mode actually covers.

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?

A single dense sentence that front-loads the verb and resource, then qualifies scope. It is efficient, though the parenthetical message list plus 'with automatic...' clause makes it slightly long for one sentence.

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 3-param tool with no annotations and no output schema, the description should clarify return shape more than 'structured JSON output'. Parse mode is covered at a high level, but the structure of validation results and failure modes remain unspecified.

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 xml, operation, and messageType with defaults and allowed values. The description only echoes the parse/validate and auto-detection semantics already present in the schema, adding no syntax or format detail beyond 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?

States a specific verb (parse/validate) plus the exact resource family (ISO 20022 XML) and enumerates the concrete message types handled (pacs.008, pain.001, camt.053). The domain is narrow enough that an agent can immediately distinguish it from parse_x12_edi or decode_gs1 despite no explicit sibling reference.

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 description makes the parse-vs-validate choice implicit by bundling both operations, and it hints at applicability to 'payment reconciliation', but it never states when to prefer this tool over adjacent format parsers or when validation is warranted instead of parsing. Usage is inferable, not spelled out.

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