data_validate

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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds useful context by stating it 'returns valid true or false without rewriting the source' and that assertions are deterministic, reinforcing that validation has no side effects. No contradiction with annotations.

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 front-loaded with purpose and usage guidance, and the three sentences are efficient. The JSON shape example is practical and earns its place, though it slightly lengthens the description.

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 complex 6-parameter tool with no output schema, the description covers the main purpose, sibling differentiation, side-effect-free behavior, and return type. Yet optional parameters like limits, workspace, and sample_rows are not addressed, so the description is not fully complete despite the rich input schema.

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?

With 0% schema description coverage, the description must compensate. It provides a concrete validation shape for source and assertions, and enumerates assertion type names, giving real semantic value for the core parameters. However, other parameters such as limits, workspace, and sample_rows are not described, leaving clear gaps.

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 opens with a specific verb ('Validate or check requirements') and clearly identifies the resource ('existing structured data'). It enumerates supported check types (non-null, unique, type, field, row count) and explicitly distinguishes from a sibling tool ('choose data_validate, not data_transform'), which is strong differentiation.

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 provides an explicit usage rule: 'choose data_validate, not data_transform, for validation-only requests.' This named alternative and clear when/when-not guidance meets the highest bar, even though it does not mention data_inspect or data_diff.

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