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

With no annotations provided, the description carries the full burden and does contribute one behavioral fact: 'The body is discarded.' However, it doesn't disclose the return value, error behavior, or whether the url/host/zone parameters have side effects, so the transparency is only partial.

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 with no filler: one states the purpose and the other adds an important behavioral detail. It is efficient and front-loaded, though arguably too terse to fully cover the tool's scope.

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 four schema parameters, no annotations, and no output schema, the description is insufficient. It only hints at the 'json' parameter and says nothing about why url, host, and zone exist or what the validation result looks like, leaving significant gaps for the agent.

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 coverage is 100%, so the baseline is 3. The description adds a small note about discarding the body, which reinforces the 'json' parameter's description, but it does not clarify the role of url, host, or zone, nor does it explain the relationship between 'body' and the 'json' field.

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 'whether a body is valid JSON', which directly conveys the tool's core function. However, it does not explicitly map 'body' to the 'json' parameter or distinguish itself from sibling tools like 'schema-url-json', leaving some potential 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?

The description offers no guidance on when to use this tool versus alternatives, no mention of exclusions, and no context about prerequisites. An agent is left to infer when validate-json is the right choice from the name alone.

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