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

The description discloses that the body is discarded after the check, which adds a significant behavior beyond the schema comments. However, with no annotations at all, the description carries the full burden for behavioral disclosure. It does not explain what the tool returns, whether it makes external requests, or whether it can operate on larger payloads. The 'discarded' trait is useful but incomplete for a full behavioral picture.

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 terse, two-sentence statement with no redundancy. It front-loads the core action. However, given the tool's nine-parameter schema, the economy crosses into under-caption: crucial information about parameter selection is omitted. Still, it is concise in form, so it avoids prose bloat and remains efficient.

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?

This definition is not complete for a tool with nine parameters, no output schema, and no annotations. The description never explains how an agent should use the other parameters or which one is the 'body'. It does not state what the agent receives after the check or under what conditions the tool is applicable. While the schema helps with the 'json' parameter, the presence of the many unrelated parameters without any explaining is a significant contextual gap, leaving the tool's interface partly opaque.

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 already provides descriptions for all nine parameters, so the schema description coverage is 100%. The tool description adds almost nothing about parameters beyond using the word 'body', which loosely corresponds to the 'json' parameter. It does not clarify the purpose of the other eight parameters (ref, url, city, feed, host, path, zone, query), leaving the meaning of those fields to the schema. This is exactly the baseline-3 scenario where the schema describes parameters and the description adds minimal value.

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, specific function: checking whether a body is valid JSON. This distinguishes it from sibling validators such as browser-url-ok or file-path-ok. However, it refers to a generic 'body' while the schema includes nine parameters, none explicitly named 'body', which creates some ambiguity about which parameter is the JSON input.

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 gives no guidance on when to use this validator versus alternatives. It does not mention any sibling tools, exclusion conditions, or typical use cases. An agent would need to infer from the name that it is the tool for JSON validation, but no positive or negative selection criteria are provided.

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