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

With no annotations provided, the description carries the full burden of behavioral disclosure. It merely states the action but does not describe the return value, error handling, side effects, or whether validation is performed as a pure read operation. The agent lacks essential information about what the tool outputs after validation.

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 a single sentence that directly states the purpose with no filler or redundant information. It is front-loaded and concise, exemplifying efficient communication.

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?

The tool has moderate complexity with three parameters and no output schema. The description does not mention what the tool returns (e.g., a boolean, list of errors, or report) or how failures are reported. This is a critical gap for an agent selecting and invoking the tool, as it cannot know how to interpret the result without additional assumptions.

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 input schema provides 100% coverage of parameter descriptions (json: 'JSON string to validate', schema: 'JSON Schema string', draft: 'Schema draft version (auto-detected if omitted)'). The tool description adds no additional parameter semantics, so the baseline of 3 is appropriate given the high schema coverage.

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 clearly states the tool's function: 'Validate JSON data against a JSON Schema.' The verb 'validate' is specific, and the resource (JSON data) and the standard (JSON Schema) are explicit. This distinguishes it from sibling tools like json-to-csv or json-expert, which serve different purposes.

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 for validating JSON data against a schema, but it does not provide explicit guidance on when to prefer this tool over alternatives, nor does it mention any prerequisites or exclusions. The usage is implied by the verb and resource, but no additional context is given.

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