Validate Test Unit

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

With no annotations, the description carries the full burden. It discloses the non-persisting side effect and the return shape ({ ok, issues }), which is essential behavioral information. It does not mention error handling or edge cases, but for a validation tool this is sufficient.

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 two sentences with no filler, front-loads the core action, and includes the key differentiator and return type. Every word earns its place.

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?

Given the opaque input schema (no defined properties) and no output schema, the description should explain more about the expected structure of 'unit' and the meaning of 'issues'. It is too sparse for an agent to reliably construct a valid input or interpret results beyond 'ok'.

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 has zero description coverage for the sole 'unit' parameter, and the description merely says 'test-unit object' without adding any field details, format, or examples. The agent cannot determine what properties the unit object must have, so the description fails to compensate for the opaque 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?

The description states a clear verb ('Validate'), a specific resource ('test-unit object'), and the criterion ('against the schema/validator rules') while explicitly noting the non-persisting behavior, which differentiates it from register_test_unit. It also gives the return shape, making the tool's purpose unambiguous.

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 phrase 'without persisting it' provides a clear usage context: use this tool to check validity before committing. However, it does not explicitly name the alternative or state when not to use it, so it falls just short of full guidance.

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