Check required keys

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

No annotations exist, so the description carries the full behavioral burden. It usefully discloses the implicit repair of text input and the reported output (missing and extra keys), but says nothing about failure behavior, whether it throws or returns a report, or the shape of the result.

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 tight sentences with no filler: the core operation and its output are front-loaded, and the usage note follows. Every clause earns its place.

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 low-complexity two-parameter tool with no output schema and no annotations, the description covers purpose, trigger, and the essence of the return value. It stops short of describing the exact report structure or error semantics, which is a minor gap given no output schema exists to carry that load.

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% and both parameters are documented in the schema ('JSON text or object', 'keys that must be present'). The parenthetical about repairing text adds a small behavioral nuance beyond the schema, but no format or syntax detail for the required-keys list is added.

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 verb (verify) and resource (required keys on an object) and adds distinguishing behaviors: text input is repaired first, and missing plus extra keys are reported. It does not explicitly name the sibling fix_json, so the agent must infer that check_keys reports rather than mutates.

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?

It gives a clear trigger context: 'Use after getting a structured answer from any model.' That tells the agent when the tool fits, but it offers no when-not guidance and never names fix_json as the alternative for pure repair work.

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