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

With no annotations provided, the description bears full responsibility for disclosing safety and side effects. The only behavioral disclosure is 'The body is discarded,' which indicates the input is not persisted. But the description does not mention whether the tool makes network requests, what happens to the other provided fields, or how validation errors are surfaced. The schema already states 'discarded after the check' for the json parameter, so this line adds no new information.

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 only two sentences, with the core action in the first sentence and a side-effect note in the second. Both sentences are short and front-loaded with the essential idea, and no filler or verbosity is present. This is appropriately sized for the tool's stated functionality.

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 nine parameters, no output schema, and no annotations, so the description is expected to provide enough context to invoke it correctly. It fails to explain which parameter carries the JSON, why the other eight parameters exist, or what the result looks like. An agent cannot reliably determine whether to use 'json,' 'path,' or some other parameter, nor what validation success/failure returns.

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 tool description adds no meaning about which parameter to use or how to construct a valid request beyond what the schema already states. The presence of unrelated fields (url, city, feed, etc.) is not explained, and the description does not clarify whether those are ignored inputs or part of a broader validation structure.

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 identifies the action: validating JSON ('Check whether a body is valid JSON'). It names a specific resource and verb, and the focus on JSON distinguishes it from sibling tools that check file paths, URLs, or timezones. However, it never explicitly compares to or disambiguates from those siblings, and the vague term 'body' leaves room for confusion against the schema's multiple parameters.

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?

No guidance is given about when to use this tool versus alternatives, when not to use it, or how to select between it and sibling tools like 'domain-shape' or 'wiki-title-ok'. There is also no mention of prerequisites or typical invocation patterns. The agent is left to infer from the name that this is for JSON validation, but nothing helps disambiguate it from the other checkers.

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