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

Without annotations, the description carries the behavioral disclosure burden. It does reveal a key trait: 'The body is discarded,' indicating the tool does not persist or transform the input. However, it does not explain what happens on invalid JSON, whether it returns a boolean/error, or any other side-effect-related details.

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?

Two short sentences with no filler. The core purpose is front-loaded, and the behavioral note about discarding earns its place. This is a model of concise description for a simple tool.

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 schema lists seven unrelated parameters, yet the description only mentions 'a body' and gives no indication of which parameter is relevant, how to invoke the validation, or what the result looks like. With no output schema and no annotations, this leaves too much unspecified for the agent to call the tool confidently.

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 covers every parameter with its own description, so baseline is 3. The description itself adds little parameter-level meaning beyond restating that the body is discarded; it does not clarify which parameter should hold the JSON or how the other schema fields relate to the validation, though the 'json' parameter description already covers that.

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 action ('Check whether a body is valid JSON') and clearly identifies the resource. It is distinct from sibling validators by focusing on JSON, but the term 'body' is not explicitly mapped to a schema parameter, leaving some ambiguity about what exactly is passed.

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 gives no guidance on when to use this tool versus the many sibling validators or shape-checking tools. There are no explicit conditions, exclusions, or alternative tool names mentioned, so the agent must infer usage context.

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