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

With no annotations, the description carries the disclosure burden. It does add a useful behavioral trait ('The body is discarded'), indicating no retention. However, it does not describe the return value, error behavior, or whether the check is purely syntactic, leaving meaningful gaps.

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, front-loaded with the action and followed by the key side-effect note. Every word earns its place.

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?

This is a 9-parameter, 0-required tool with no output schema and no annotations. The description does not clarify the relationship between the many 'discarded' params and the body being validated, nor state what the caller should expect back. An agent can invoke it only by assuming `json` is the relevant parameter.

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 covers 100% of parameters with descriptions, so the baseline is 3. The description itself adds no parameter-level meaning; it does not even identify which parameter is the 'body' (presumably `json`). It neither helps nor hurts 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 description uses a specific verb ('Check whether') and resource ('a body is valid JSON'), making the core function unmistakable. It also states the body is discarded, which separates this from tools that consume or store the body. The name alone is reinforced, not merely restated.

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?

The description implies the obvious use case—any time a body's JSON validity needs confirmation—but it gives no when-to-use guidance versus alternatives and names no sibling tools. For a simple validator, this is adequate but not explicit.

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