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

With no annotations, the description must carry the behavioral disclosure burden. It does add one useful behavior—'the body is discarded'—indicating no persistence. However, it does not disclose what the tool returns, whether it throws an error, or what the success/failure signal looks like.

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 sentence with no filler. The core operation is front-loaded, and the note that the body is discarded is relevant and concise.

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 sparse for a tool with four parameters, no annotations, and no output schema. It does not explain which parameter supplies the body, what the result format is, or how to handle the three seemingly unrelated parameters. An agent cannot reliably construct a correct call from this description alone.

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 `json` parameter description confirms it is the JSON text to validate, but the tool description says 'body' without linking to that parameter. The unrelated `url`, `host`, and `zone` parameters add confusion and are not reconciled with the described behavior.

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 clearly names a validation operation on a JSON body, which distinguishes it from the sibling tools such as normalize-url, timezone, and uuid-v4. However, it never maps 'body' to the schema's `json` parameter, leaving some ambiguity about the actual input.

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 tool's purpose: use it to check if a body is valid JSON. It provides no explicit when-to-use guidance, prerequisites, or comparison to alternatives, but the sibling list contains no other JSON validator, so the omission is not critical.

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