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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses rate limits (5 free calls/day), the subscription model (feature payments unlimited), the credit-based fallback (1 credit = 10 further validations), and the mandatory account requirement. This is rich behavioral context an agent cannot get from annotations alone.

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?

Purpose is front-loaded and the output summary is efficient, but the pricing/subscription explanation spans three sentences and is comparatively verbose for a definition where the schema and annotations already carry much of the load.

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, annotations covering the safety profile, and 100% parameter coverage, the description fills the remaining gap (cost/limit/auth) and leaves nothing an agent needs to call 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 description coverage is 100%, so both input alternatives (xml vs file_base64), the profile enum, and filename are fully documented in the schema. The description adds no parameter detail beyond what the schema already provides; 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 (prüft/validates) and resource (Zahlungsdatei pain.001) with scope qualifiers (SEPA-Überweisung, Auslandszahlung AXZ, versions .09/.03). An agent can distinguish it from validate_bank_statement without opening either schema.

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 implies usage through the pain.001 scope and the credit note covering 'payment files and bank statements together', but it never names an alternative tool or states when NOT to use this one. Usage guidance is only implicit.

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