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

The description explicitly discloses that the body is discarded, which is meaningful side-effect transparency given no annotations are present. However, it does not state what the tool returns (boolean, error, status) or whether validation is purely syntactic, leaving the no-annotation safety and outcome profile only partially described.

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 purpose is front-loaded. The second sentence about discarding is useful and earns its place, though the overall terseness borders on under-specification.

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?

With no output schema, the description must communicate what the caller receives, but it does not say whether the tool returns a boolean, an error, or some other result. It also does not clarify how the many optional schema parameters interact with 'body' or when to prefer this tool over sibling validators, leaving a meaningful completeness gap.

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 only a general 'body is discarded' lifecycle note and does not clarify which parameter carries the JSON text; the schema's `json` parameter already provides the needed semantic, so the description adds no real value beyond the schema.

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 first sentence states a concrete action ('check') and object ('whether a body is valid JSON'), going beyond merely restating the tool name. It does not connect 'body' to the schema's `json` parameter or contrast with sibling validators, so it is not a 5.

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 instead of sibling tools, no mention of what counts as the input body, and no exclusions or prerequisites. The only implied context is the tool name and one-line purpose, which provides no real decision support.

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