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

Annotations already mark the tool as idempotent and read-only, so the safety bar is covered. The description adds the explicit behavior that the input body is discarded after validation, which is useful, non-obvious context about data handling. There is no contradiction with the annotations.

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 the core action front-loaded and the disposal behavior in the second sentence. No filler, redundancy, or unnecessary detail.

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?

For a simple validation tool, the core purpose and side effect are given, but the description never maps 'body' to a specific input parameter and does not state the result shape for valid versus invalid JSON. Given the broad input schema and no output schema, this is minimally viable but not complete.

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 input schema already documents each property with descriptions, including 'json': 'JSON text to validate; discarded after the check', so schema coverage is high. The description's generic 'body' adds no parameter-level meaning beyond what the schema provides, matching the baseline.

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 names a specific operation ('check') and resource ('valid JSON body'), making the tool's function immediately clear. It is easily distinguished from sibling shape validators such as domain-shape or jira-key-shape, which cover other formats.

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 use case of checking JSON validity is implied by the purpose statement and the discard note, but the description does not state when-not-to-use it or name any alternative tools. It gives clear context for one straightforward scenario, but no explicit routing.

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