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

The description explicitly discloses a key behavioral trait: 'The body is discarded.' This goes beyond a simple statement of function and is important for agents concerned with side effects or persistence. Since no annotations are provided, this disclosure carries the full transparency burden, though it could also mention return format or error 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 two short sentences that waste no words. The primary action is front-loaded, and the discard note adds critical information without bloating the text. 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?

The description is too sparse given the schema's eight parameters. It doesn't explain which parameter to pass, why the other parameters exist, or what the tool returns. There is no output schema, and the description doesn't specify return value or behavior for invalid JSON, leaving gaps for an agent trying to invoke it 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?

All schema parameters have descriptions, so schema coverage is high and the baseline is 3. The description does not add meaning beyond the schema; it uses the term 'body' while the schema refers to the 'json' parameter, creating a slight mapping gap. It doesn't clarify which parameter is actually used for validation, leaving the agent to rely solely on 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 states a clear verb and resource: 'Check whether a body is valid JSON.' This distinguishes it from sibling validators like file-path-ok or wiki-title-ok. However, the generic term 'body' and the presence of many unrelated schema parameters introduce slight ambiguity, so it doesn't fully achieve a 5.

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 a validation use case but provides no explicit guidance on when to use this tool versus alternatives, nor any exclusions. For example, it doesn't say 'Use this when you need to verify JSON syntax before parsing.' The need is inferred from the name and description.

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