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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions output categories but does not state that inputs must be valid JSON strings, what happens on invalid input, how nested structures or arrays are handled, or whether the operation has side effects. This is a meaningful transparency gap for a 2-parameter 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 a single, front-loaded sentence with no filler words. It is efficient and easy to scan, though it omits important parameter details that would justify a 5.

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?

An output schema exists, so return values do not need to be described, but the input semantics are under-specified and there is no annotation coverage. For a tool with two required parameters and 0% schema description coverage, the description is not complete enough to guarantee correct invocation on the first attempt.

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 0%, so the description must compensate. It only calls the inputs 'two JSON values' and never clarifies that a and b are expected as serialized JSON strings, or what validity constraints apply. An agent would have to guess how to populate these parameters correctly.

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 uses a specific action ('Diff') and a clear resource ('two JSON values'), and it states the kind of result (added/removed/changed keys). This distinguishes it well from the encoding and formatting siblings, though it does not explicitly contrast with any sibling tool.

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 about when to use this tool versus alternatives, nor are there any prerequisites or exclusions. The intended use case—comparing two JSON values—must be inferred from the purpose statement alone.

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