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

With no annotations, the description carries full burden. It only discloses that 'The body is discarded,' but says nothing about whether the operation is read-only, what happens on invalid JSON (error vs. boolean result), or any side effects on other parameters. It doesn't mention that other inputs are also discarded or that no external calls occur.

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 sentences with no fluff. The primary purpose is front-loaded, and the behavioral note about discarding is a single clause. Every word earns its place; it's appropriately sized for a tool of this apparent simplicity.

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 and no output schema or annotations, the description is far too minimal. It doesn't explain how the other parameters relate to the JSON check, what the return value looks like, or any prerequisites. An agent receiving a URL or city name would have no clue whether to invoke this tool. The description is incomplete for the tool's actual complexity.

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 detail beyond what the schema already provides; it doesn't clarify that 'json' is the key parameter for JSON validation or explain the purpose of the other 8 parameters. It neither enhances nor detracts from the schema.

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 action: 'Check whether a body is valid JSON.' This is a clear verb and resource, and the name reinforces it. However, it doesn't differentiate from sibling validation tools like file-path-ok or domain-shape, and the presence of 9 unrelated parameters in the schema could confuse an agent about the true scope, which is not addressed.

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 on when to use this tool vs. alternatives. It doesn't state that this should be used only for JSON validation, nor does it mention any exclusions or when another sibling would be more appropriate. The description leaves the selection entirely to the agent's inference.

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