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

With no annotations available, the description carries the full burden for behavioral disclosure. It does disclose one meaningful behavior: the body is discarded after the check. However, it does not explain what the tool returns for valid versus invalid JSON, whether it accepts any JSON type, or how errors are reported, leaving important behavioral details unspecified.

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 that front-load the core purpose and immediately follow with a key behavioral caveat. There is no wasted wording or irrelevant detail.

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 has no output schema and no annotations, so the description must provide enough context for correct invocation. It does not state the return format, what counts as valid JSON, or which parameter should be populated, and the presence of four optional, seemingly unrelated parameters increases the need for clearer guidance. The description is too sparse to be considered complete.

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 already documents all four parameters. The description adds little beyond the schema: 'The body is discarded' echoes the json parameter's existing 'discarded after the check' note. It also fails to clarify why url, host, and zone parameters appear in a validate-json tool, which could confuse an agent about which fields are actually relevant.

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 specific action ('Check whether a body is valid JSON') and a clear resource ('a body'). It is distinct from all sibling tools, which deal with URLs, timezones, and similar concerns, so an agent can immediately tell what this tool does and that it is not redundant with its siblings.

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 clear context: use this tool when you need to validate JSON and do not need the body afterward, since it is discarded. It does not explicitly name alternatives or exclusion conditions, but the sibling set contains no other JSON-validation tool, so the lack of an explicit 'use this instead' is not a serious gap.

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