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

With no annotations, the description must fully disclose behavior. It states that 'The body is discarded,' implying a read-only, side-effect-free operation, which is helpful. However, it does not mention whether the tool performs network access, validates against a schema, or how it reports results (e.g., boolean vs. error), leaving significant 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?

The two sentences are extremely concise and front-loaded, with the purpose stated first and the discard behavior second. Every word earns its place, and no fluff or redundant phrasing exists.

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?

For a tool with 9 parameters, no output schema, and no annotations, the description is incomplete. It fails to clarify that only the 'json' parameter is relevant, what constitutes 'valid JSON' (syntax only or structural), or the return format. Agents could easily misapply it, and the mismatch between 'body' and the 'json' parameter adds confusion.

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 schema documents all 9 parameters, including that 'json' is the text to validate. The description adds no extra value to parameter meaning; in fact, it introduces ambiguity by using 'body' instead of 'json.' The baseline of 3 applies, as the schema carries the semantic weight.

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 ('Check') and resource ('body is valid JSON'), which identifies the tool's primary function. However, it does not differentiate from sibling shape-checking tools like 'compatibility' or 'domain-shape', and it refers to 'body' while the schema parameter is 'json', which could cause minor confusion.

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?

No guidance is provided on when to use this tool versus its many siblings. The description gives no context about typical use cases, prerequisites, or alternatives, leaving the agent to infer the tool's role from its name alone.

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