validate_tdd_ae

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

With no annotations, the description carries the full burden of behavioral disclosure, and it clearly discloses the non-obvious trait that this tool always returns an explicit 'unavailable' result. This prevents an agent from expecting a real validation outcome and gives the reason why. There is no annotation contradiction.

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 description is only two sentences, front-loads the purpose, and immediately warns about the stub behavior. Every sentence earns its place and there is no 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?

For a one-parameter tool with full schema coverage and an output schema, the description provides the essential behavioral context: it always returns unavailable. It does not mention sibling validate_invoice_ae for comparative routing, but nothing about how to invoke the tool or what outcome to expect is missing.

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?

The schema already fully describes the single xml parameter as 'Raw Peppol AE Tax Data Document (TDD) XML content' at 100% coverage. The description's 'Raw' and TDD wording adds no meaningful semantics 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?

The description names a specific operation and resource: validating a Peppol AE Tax Data Document (TDD), which is distinct from the sibling validate_invoice_ae. The second sentence clarifies the actual available behavior (always returns unavailable), so there is no ambiguity about what the tool is for.

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 does not explicitly state when to use this tool instead of alternatives, nor does it name validate_invoice_ae as the route for Peppol invoice validation. However, the explicit note that no TDD validation is currently available implies an agent should not expect real validation from this tool, which is an implicit usage signal.

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