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

With no annotations present, the description carries the burden of behavioral disclosure. It usefully states that the body is discarded after the check, implying no retention or side effects. However, it does not describe the return format, error behavior, or what 'valid' means beyond basic JSON syntax.

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 a single front-loaded sentence with no wasted words. It communicates the core purpose and the key side-effect efficiently.

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 plus schema is mostly sufficient, but the term 'body' does not map directly to any schema property, and the purpose of the many unrelated parameters is left unexplained. The lack of an output schema and absence of usage guidance leave room for agent uncertainty about return values and invocation.

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 input schema descriptions fully cover all seven parameters, including the 'json' parameter as 'JSON text to validate; discarded after the check.' The description adds no parameter-level meaning beyond the schema, so the baseline of 3 applies.

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 action ('Check whether a body is valid JSON') that clearly identifies the tool's core function. It distinguishes the tool from sibling validators through the explicit JSON focus, though 'body' is slightly ambiguous compared to the schema's '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?

No guidance is provided about when to use this tool versus alternatives like domain-shape or file-path-ok. The description implies 'use this when you need to validate JSON,' but it does not state exclusions, alternatives, or context for choosing among related validators.

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