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

With no annotations, the description carries the full burden of behavioral disclosure. It mentions that 'The body is discarded', which is a positive disclosure, but it fails to describe the return value (e.g., boolean success/failure), any error behavior, or the role of the other eight parameters. The description is silent on side effects, permissions, or whether the tool modifies any state, making it insufficient for a tool with no annotations.

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 sentences with no filler. The core purpose is front-loaded ('Check whether a body is valid JSON') and the disposal note is concise. Every word earns its place, making it highly efficient.

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 complexity of 9 optional parameters, no annotations, and no output schema, the description is markedly incomplete. It does not specify what the tool returns, how the 'body' maps to the schema's parameters, or why unrelated parameters exist. An agent cannot confidently call this tool correctly without inferring which parameter is the JSON body and what response to expect. The description leaves significant gaps that could lead to misuse.

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 schema has 100% description coverage, so each parameter is documented. The description adds 'The body is discarded' which partially aligns with the 'json' parameter's schema description ('discarded after the check'), but it does not add new meaning beyond the schema. The description does not clarify why the tool accepts many unrelated parameters (e.g., 'city', 'url'), leaving the semantics of those parameters unexplained in the description itself. Since the schema covers the basics, a baseline 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 verb 'Check' and the resource 'a body' with the specific validation for JSON. It is not a tautology and conveys the core function. It does not explicitly differentiate from sibling validation tools like 'file-path-ok' or 'url-path-ok', but the JSON focus is unambiguous. The phrase 'The body is discarded' adds clarity about the tool's non-preserving nature.

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 explicit guidance on when to use this tool versus alternatives. The description does not mention conditions, exclusions, or alternative tools. The only implicit usage is that it checks JSON validity, but no context is provided about when an agent should prefer it over other validation tools or how it relates to the many unrelated parameters in the schema.

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