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

The description usefully discloses that 'the body is discarded,' which is a meaningful behavioral trait not visible in the tool name. However, with no annotations and no output schema, it says nothing about the return value, error behavior, or what happens with invalid JSON, so the description only partially carries the behavioral disclosure burden.

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?

Two short, front-loaded sentences with no filler. The purpose is stated first, followed by a useful behavioral caveat. Every sentence earns its place.

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?

A 4-parameter tool with no required parameters, no annotations, and no output schema needs more than this. The description does not explain what 'body' refers to, what result the agent should expect, or how url/host/zone relate to validation, leaving an agent under-informed for invocation.

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 baseline is 3. The description adds no parameter-level meaning. The schema descriptions for url, host, and zone appear unrelated to JSON validation, creating ambiguity that the description does not resolve.

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 the core function clearly: 'Check whether a body is valid JSON' with a specific verb and resource. It is distinguishable from siblings like normalize, cite, and scrape, but it does not explicitly differentiate itself from any validation-related alternative, so it misses a 5.

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 guidance on when to use this tool versus the sibling tools, nor any exclusions or contexts where a different tool would be preferable. An agent can only infer that it should be used for validating JSON, but the description does not spell this out.

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