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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that 'the body is discarded,' hinting at no side effects, but it does not explain what happens on valid vs invalid JSON, what the return value is, or whether any other parameters are actually used. The schema's per-parameter 'discarded after' notes add some context, but these come from the schema, not the description, and are not synthesized.

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 a single, short sentence that front-loads the main function. It is concise but under-specified. It omits essential context about parameter usage, return format, and alternatives, making it more of an under-specified statement than a genuinely efficient description.

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 the tool has 9 parameters, no annotations, and no output schema, the description is severely incomplete. It fails to clarify why the extra parameters exist, what the tool returns, or how to invoke it correctly. An agent cannot confidently call this tool based solely on the description, as the mismatch between the JSON-focused text and the broad parameter list is unresolved.

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?

The schema has 100% description coverage, so each parameter is documented. The description itself adds little meaning beyond the schema; it only refers to 'a body' without clarifying that the 'json' parameter is the primary input. The tool description does not help the agent understand why the other eight parameters exist or how they relate to JSON validation, leaving the parameter list confusing.

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 clear verb and resource: 'Check whether a body is valid JSON.' It is distinct from sibling validators like domain-shape or jira-key-shape, which target other formats. However, the schema includes 9 unrelated parameters (e.g., ref, city, feed) that are not mentioned in the description, muddling the tool's actual scope and creating ambiguity about what exactly is validated.

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 provides no guidance on when to use this tool versus alternatives. It does not mention other validation tools, nor does it state any conditions or exclusions (e.g., 'use for JSON only, not for URLs'). The presence of many sibling tools makes this gap significant.

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