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

No annotations are provided, so the description bears the full burden. It discloses that 'the body is discarded,' which is a useful behavioral note, but it does not mention side effects, return values, or whether other parameters are ignored. Given the schema's diverse parameters, the description does not clarify what happens with non-JSON inputs, leaving behavioral expectations ambiguous.

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—two short sentences with no wasted words. It front-loads the core purpose and includes a behavioral note. This is appropriately sized for the minimal information provided.

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 nine parameters, no annotations, and no output schema, the description is incomplete. It does not explain the role of each parameter, which ones are used for JSON validation, or what the tool returns. The mismatch between the description and the schema's parameter list leaves significant gaps for an agent to resolve.

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 covers all parameters with descriptions, so the baseline is 3. The tool description adds no parameter-specific meaning; it does not indicate which parameters are relevant for JSON validation or how they relate. The schema descriptions themselves mention 'discarded' for many fields, so the tool's description adds nothing beyond that.

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') and the resource (JSON body). It is specific about the tool's primary function, and the mention of discarding the body adds context. However, the schema includes nine unrelated parameters (ref, url, city, feed, host, path, zone, query) that do not align with JSON validation, creating ambiguity about the tool's actual scope. This prevents a 5, as it does not fully distinguish from sibling shape-checking tools.

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 offers no guidance on when to use this tool versus alternatives like domain-shape or jira-key-shape. It does not state explicit conditions or mention any sibling tools. The usage is only implied by the name and description, leaving the agent to infer that it is for JSON validation, which is insufficient for clear selection.

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