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

The description states 'The body is discarded,' implying the input is not retained, but it does not disclose whether the operation is read-only, what it returns, or any side effects. With no annotations provided, the description carries the full burden and is inadequate for understanding the tool's behavior.

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, concise and front-loaded, stating the purpose immediately and adding a side note about discarding. There is no unnecessary content, though it is so terse it omits critical context. It earns its place but could be more informative.

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?

Given 9 parameters, no output schema, and no annotations, the description is severely incomplete. It does not explain how the various parameters relate to JSON validation, what the expected input format is, or what the tool returns. The schema helps but does not resolve ambiguity about which parameters are relevant, making it hard for an agent to call correctly.

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 description does not mention any parameters directly. The input schema has 100% coverage, so each parameter has a description. The tool description adds no additional meaning beyond the schema and could be ambiguous about which parameter corresponds to 'a body.' Baseline 3 applies due to full schema coverage.

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 states the action: 'Check whether a body is valid JSON.' This identifies the verb and resource, and the tool name reinforces it. However, it does not differentiate from sibling validators like domain-shape or github-repo-shape, and the schema includes many unrelated parameters, creating slight ambiguity about scope.

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 gives no guidance on when to use this tool versus alternatives. There is no mention of conditions, exclusions, or sibling tools. An agent must rely on the name and schema alone, which is insufficient for a tool with many similar validators.

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