aws_resource_diff

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

The description adds substantial behavioral context beyond the annotations: 'No mutation is sent to AWS', simulation happens in memory, moved/copy/test operations are rejected at schema validation, and CCAPI accepts those operations but the tool simply doesn't simulate them locally. This goes well beyond the readOnlyHint/idempotentHint annotations and clearly sets expectations for side effects and limitations.

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 information-dense but every sentence earns its place: core purpose, safety guarantee, usage guidance, and operation-subset limitations are all covered in four sentences. The most critical fact ('No mutation is sent to AWS') is front-loaded early, and the alternative tool is named rather than implied.

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?

Despite no output schema, the description tells the agent what to expect from the call ('before/after plus a flat list of changed paths'). It covers the tool's purpose, side-effect safety, input constraints, and the fallback path for unsupported operations. For a tool of this complexity, nothing critical is missing.

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 meaningful semantics beyond the schema by explaining the patchDocument subset semantics, clarifying that add/replace need a value, and explicitly routing move/copy/test away from this tool. This is more than redundant parameter restatement, but not a full re-documentation of each parameter.

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: 'Dry-run a CCAPI update', with explicit mechanics ('fetch the current resource state, simulate applying a JSON Patch in memory, and return before/after plus a flat list of changed paths'). It also distinguishes itself from aws_resource_update by emphasizing no mutation is sent to AWS, so an agent can immediately tell this tool apart from its siblings.

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 description explicitly says 'Use this before aws_resource_update to verify the patch does what you expect' and provides a clear exclusion: 'move'/'copy'/'test' operations should use aws_resource_update directly. This gives the agent explicit when-to-use and when-not-to-use guidance with named alternatives.

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