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

With no annotations provided, the description carries the full burden. It does disclose that the body is discarded, but it does not explain what happens on invalid JSON, whether the check is local or network-based, or what response/error shape to expect. The discard note also largely repeats parameter descriptions in the schema.

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 the purpose front-loaded and no filler. The discard note is concise, though it is already reflected in parameter descriptions.

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 definition is too thin for a tool with 9 optional parameters, no annotations, and no output schema. It does not clarify which parameter is the 'body', why the other eight parameters exist, or what a successful/failed validation returns, leaving an agent to guess.

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; the description adds no parameter-level detail. It also introduces the ambiguous term 'body' without mapping it to the 'json' property, though the schema itself clarifies 'JSON text to validate'.

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 clear action and target: 'Check whether a body is valid JSON'. This is specific enough to distinguish it from sibling shape/URL/path validators, though it does not explicitly name any sibling or the 'json' parameter.

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 guidance on when to use validate-json versus alternatives, what scenarios call for it, or which parameters are relevant. The description only states the action and discarding side effect.

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