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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description goes further by disclosing rate limits/credit consumption and the auth requirement (an account is always needed), plus what each run returns (per-file message, version, rule findings, schema check with line/column, overall verdict), which is context the annotations do not carry.

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?

The purpose and supported formats are front-loaded, and the semicolon-separated clauses each carry distinct information (formats, output, pricing, auth). It is dense and somewhat long, but little of it is filler.

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?

With an output schema present and full parameter coverage, the definition needs only to cover scope, cost and prerequisites, all of which it does. The only gap is the lack of explicit routing against the sibling validate/parse tools.

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 xml, filename and file_base64 are fully documented in the schema. The description only adds that multiple files may be supplied as a ZIP, which matches the base64 field's own text; baseline 3 applies when the schema does the heavy lifting.

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?

Names a specific verb ("Prüft") plus the exact resources validated (Kontoauszüge, Kontoberichte, Avise, Gebührenabrechnungen) and even pins the message types/versions (camt.052/.053/.054/.02/.08, camt.086). This clearly separates it from sibling parse_bank_statement, which reads rather than validates.

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?

It gives cost/limit context (free up to 5 calls/day, subscription removes the limit, 1 credit buys 10 checks) and that an account/API key is always required, which is useful operational guidance. However it never states when to choose this over parse_bank_statement or validate_payment_file, so the when/when-not routing is only implied.

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