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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does disclose one meaningful trait—'the body is discarded'—which signals that the input is not retained after the check. However, it does not describe what happens on invalid JSON, what the agent receives back, or any other side effects, leaving only minimal transparency.

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 sentences with no filler, and the core action is front-loaded. The second sentence about discarding the body is a legitimate behavioral note rather than padding.

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 simple validation tool, the description covers the primary action and non-retention, and the schema fully documents parameters. However, there is no output schema and the description never states what the agent receives as a result, nor does it clarify how to reconcile the body with the four schema fields.

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?

Schema description coverage is 100%, so the baseline is 3 even though the description adds no parameter-level detail. The description references 'body' but never maps it to the 'json' property, and the url, host, and zone parameters are present in the schema but unaddressed by the description.

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 concrete action ('Check whether a body is valid JSON') with a clear resource and outcome, and it is easily distinguished from sibling tools like normalize-url or timezone. However, it uses 'body' rather than the schema's 'json' parameter, leaving slight ambiguity about which input is being validated.

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?

There is no explicit guidance on when to use validate-json versus any alternative, nor any exclusions or prerequisites. The note that the body is discarded implies a validation-only operation, but the description does not explain when this tool should be selected over others or what context it is appropriate for.

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