Invalid test values

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

No annotations exist, so the description carries the full burden, and it does disclose two important traits beyond the schema: determinism ('Same seed, same output for the same catalogue version') and the output shape ('each with the reason it is invalid'). It does not state that the call is side-effect-free or whether any auth is needed, which leaves a small gap for a generation tool.

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?

Three sentences, all front-loaded: purpose first, then the reason field, then determinism, then placement in the workflow. No sentence repeats the name or restates the schema.

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 5 parameters including a nested chaos object and no output schema, the description supplies purpose, determinism, and workflow position, which is most of what an agent needs. The chaos behaviour (failure injection, latency, empty results) is only discoverable in the schema, so the description is not fully self-sufficient for error-handling tests.

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 80%, so the baseline is 3; the description goes beyond it by naming the concrete value families behind the kind enum (email, card, address, unicode, iban, ssn) and by explaining that 'reason' accompanies each value via the fields filter example. The nested chaos object and its injection semantics are left entirely to the schema.

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 resource and a distinguishing modifier: 'Deliberately invalid TEST DATA values', enumerating the categories (malformed emails, Luhn-invalid cards, Unicode edge cases, IBAN/SSN shapes). This clearly separates it from the sibling generate_test_data, which produces valid data.

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?

Gives explicit sequencing: 'Use it after generate_test_data, to test that your validation rejects bad input. Next: sandbox_create, then sandbox_payments, to test a payment flow.' Both the triggering condition and the downstream alternatives are named, so routing is unambiguous.

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