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

With no annotations, the description carries the full burden, and it does contribute one meaningful behavior: the body is discarded. However, it does not disclose the return format, error behavior, network effects, or whether validation is local, so behavioral transparency is incomplete.

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 short, front-loaded sentences with no filler. The first sentence states the purpose and the second adds a non-obvious behavioral trait, so every sentence 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?

There is no output schema, yet the description never states what the tool returns, such as a boolean, verdict, or error message. It also fails to map 'body' to the actual `json` parameter or explain the role of the six other schema fields, leaving the definition incomplete for a 7-parameter tool.

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?

All seven parameters are already described in the input schema, including `json` as 'JSON text to validate; discarded after the check.' The description itself adds no parameter-level meaning and even introduces ambiguous 'body' terminology, but the high schema coverage keeps this at the baseline score.

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: check whether a body is valid JSON. It is distinguishable from sibling validation tools because of the explicit JSON focus. However, it uses the vague term 'body' rather than naming the actual `json` parameter, which prevents a perfect score.

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 about when to use this tool versus alternatives such as domain-shape or file-path-ok. It also fails to mention any prerequisites, exclusions, or conditions for choosing validate-json, leaving usage decisions entirely to the agent.

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