openDiff

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

The description explicitly discloses the side effect of creating temporary files on disk, which goes beyond the destructiveHint annotation. It provides clear behavioral context without contradicting the annotation.

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 concise sentences that convey the essential purpose and side effect without extraneous information. Every sentence adds value.

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?

The description is mostly complete for a simple diff tool, but it does not explain how temporary files are managed (e.g., cleanup) or what the diff view looks like. Given the lack of output schema, these details would enhance completeness.

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?

All four parameters have descriptions in the input schema (100% coverage), so the description adds no additional meaning. The baseline of 3 is appropriate given the schema coverage.

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 clearly states the tool opens a diff view comparing old and new file content, with the specific verb 'Open' and resource 'diff view'. It also mentions creating temporary files, distinguishing it from sibling diff tools like getDiffBetweenRefs or getDiffFromHandoff.

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 implies usage for comparing file contents but does not provide explicit guidance on when to use this tool over alternatives like getDiffBetweenRefs or getDiffFromHandoff. No 'when not to use' or alternative suggestions are included.

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