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

The description discloses one behavioral trait: the body is discarded after the check. However, it does not mention what the tool returns (e.g., boolean, success/error), whether there are side effects, or the safety profile. With no annotations available, the behavioral burden falls entirely on the description, and it only partially addresses it.

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 the core action immediately stated and the behavioral note about discarding placed right after. There is no filler or extraneous detail. It earns high marks for economy and clarity despite being thin.

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 required parameters, nine optional parameters, no output schema, and no annotations, the description leaves the agent without enough context. It fails to identify which parameter carries the JSON body, why the other eight exist, or what successful validation looks like. This is a substantial completeness gap for a multi-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?

The schema description coverage is 100%, and every parameter has an individual description, which already explains each parameter's meaning. The tool's description adds no extra semantic value beyond that. The schema's own description of 'json' ('JSON text to validate; discarded after the check') is what communicates the core input, so the baseline 3 is appropriate.

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 specific verb and resource: 'Check whether a body is valid JSON.' It is clear enough to distinguish this as a JSON validation tool by intention, but it does not explicitly differentiate itself from sibling validation tools like domain-shape or browser-url-ok. The word 'body' is slightly ambiguous but not a tautology.

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 its siblings, nor what input condition selects it. The description gives no usage context, no prerequisites, and no references to alternatives. An agent is left without direction on when this tool should be chosen.

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