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

With no annotations, the description must fully disclose behavioral traits. It mentions that 'the body is discarded,' which implies no persistence, but it does not state what is returned (likely a boolean), whether there are side effects, or how the other parameters are handled. Moreover, the description refers to a 'body' while the schema has a 'json' parameter, creating ambiguity about what exactly is validated. This lack of clarity is a significant gap for a validation tool.

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 extremely concise: two short sentences with no filler. The key point (validation and disposal) is front-loaded. However, it is so brief that it omits important behavioral and contextual details, though conciseness itself is well-executed.

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 required fields, no output schema, and no annotations, the description is far too minimal. It does not explain what the tool returns, how the parameters are used, or why there are so many seemingly unrelated parameters. An agent would be unsure how to construct a valid call or interpret the result. The description is inadequate for the complexity of the schema.

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 100%, so each parameter has a description in the schema. The tool description adds no extra meaning beyond that. It does not clarify how parameters like ref, url, city, or feed relate to JSON validation, leaving the agent to infer their relevance. Since the schema already documents them, the description's lack of contribution is acceptable but not helpful.

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 specifies the validation action and the object being validated. However, it does not differentiate from sibling validators like domain-shape or jira-key-shape, which all check shapes of different input types. The name 'validate-json' hints at the distinction, but the description does not explicitly contrast it with alternatives.

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 provided on when to use this tool versus other validation tools. There is no mention of alternative tools, prerequisites, or exclusions. The description is a bare statement of purpose without any context about appropriate use cases or when to avoid it.

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