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

The statement 'The body is discarded' usefully signals that the tool is non-destructive and does not retain input. With no annotations provided, the description carries the full burden, yet it omits any mention of return behavior, error handling, or side effects. It gives partial transparency enough to avoid expecting persistent changes but not enough to fully understanding outputs.

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 extremely concise, using two short sentences. Each carries value: the first states its purpose, the second adds a non-trivial behavioral note. While the choice of 'body' could be refined, the overall structure is efficient and scannable.

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 the tool has 9 parameters, none required, and no output schema, the description is incomplete. It does not map the 'body' to any specific schema parameter, nor does it mention what the tool returns (e.g., a boolean) or whether the other parameters are simply ignored. An agent would struggle to invoke the tool correctly without groggling through the schema.

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%, with each parameter already carrying a specific description (e.g., 'json' as 'JSON text to validate; discarded after the check'). The tool description adds no additional semantic meaning beyond the schema, so the baseline score of 3 is appropriate.

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 tool's purpose with a specific verb ('Check') and object ('a body is valid JSON'). While it doesn't explicitly distinguish from sibling validation tools, the name 'validate-json' and the description together are informative. However, it uses the word 'body' rather than referring to the 'json' parameter in the schema, which introduces slight ambiguity.

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?

There is no guidance on when to use this tool versus the many sibling validators (e.g., domain-ok, file-path-ok), nor any mention of which parameter holds the JSON to validate. The description gives no context for selection, so an agent must infer this from the schema alone.

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