aws_resource_diff

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, openWorldHint. Description adds that no mutation is sent, simulation is in-memory, and the supported subset (add/remove/replace). No contradictions. Adds value beyond 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?

The description is concise: two main sentences covering purpose, usage, and limitations. No fluff. Front-loaded with core action. 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 tool with 6 parameters (3 required), annotations, and no output schema, the description fully covers when to use, what it does, what it returns, and its limitations. It also references the sibling tool appropriately. Sufficient for correct invocation.

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% with descriptions on all parameters. Description enhances 'patchDocument' by explaining it supports only add/remove/replace and rejecting move/copy/test. This adds meaning beyond the schema's enum listing.

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 specific verb-resource phrases: 'Dry-run a CCAPI update', 'fetch current state', 'simulate applying a JSON Patch', 'return before/after plus changed paths'. It clearly distinguishes from the update tool by noting this is a preview.

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?

Explicitly states 'Use this before aws_resource_update to verify the patch does what you expect.' Also indicates when to use the sibling directly: 'use aws_resource_update directly if you need move/copy/test'. Provides clear context and exclusions.

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