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

No annotations are present, so the description carries the full burden. It does disclose that 'The body is discarded,' which is a useful behavioral trait, but it does not indicate return values, behavior on invalid JSON, or whether other schema parameters affect the check.

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 exactly two short sentences: one declares the operation and one declares the side effect. There is no fluff, and the key action is front-loaded.

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 input schema contains many seemingly unrelated parameters (url, city, feed, host, path) with their own discard annotations, but the description does not explain which parameter is 'the body' or why the other parameters exist. With no output schema and no annotations, this ambiguity is a significant gap for correct 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 coverage is effectively 100%, with each parameter documented in the input schema. The description adds no parameter-specific meaning beyond referring to 'a body,' so the baseline of 3 applies because the schema already provides the necessary semantics.

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 verb and resource: 'Check whether a body is valid JSON.' This is immediately distinct from sibling shape validators like domain-shape or figma-url-shape, and the discard note adds a clear side effect.

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 explicit when-to-use or when-not-to-use guidance, and no mention of alternatives among the many shape-check sibling tools. The purpose implies usage for JSON validation, but the description leaves the agent to infer selection criteria.

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