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

With no annotations, the description carries the transparency burden. It discloses one behavior—'The body is discarded'—but does not explain what the caller receives on valid vs invalid JSON, whether errors are thrown, or any other side effects/limits.

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, immediately states the core action, and contains no filler or redundant words. It is well-suited to the simple validation task.

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 tool is simple, but the description omits the result/return behavior entirely. Saying 'body is discarded' does not clarify whether the tool returns a boolean, a success status, or an error for invalid JSON, and no output schema is provided to fill that gap.

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?

Input schema description coverage is 100%, so the baseline is 3. The schema's 'json' field is described as 'JSON text to validate; discarded after the check', which is relevant. However, the description itself says 'body' rather than referencing the 'json' parameter and the other eight optional fields are unrelated to JSON validation, creating potential confusion.

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 explicitly states the tool's function: 'Check whether a body is valid JSON.' This is a specific verb and object, and the name 'validate-json' reinforces it. However, 'body' is ambiguous—it is not mapped to any input parameter, and the tool could be clearer about whether it validates the request payload or a string in the 'json' field.

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 gives a basic purpose but no guidance on when to choose this tool over the many sibling validators (e.g., file-path-ok, browser-url-ok, search-query-len). It does not mention conditions, alternatives, or pre-requisites, so an agent has to infer when JSON validation is needed.

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