Show diff (side-by-side image)

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

No annotations are provided, so the description carries full burden. It discloses that the tool returns a picture (not text) and is shown inline, but it does not discuss potential limitations (e.g., empty diffs, large outputs), permissions, or side effects. The disclosure is adequate but not exhaustive.

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 two sentences long, highly efficient, and front-loaded with the core purpose. Every sentence adds value without redundancy or unnecessary elaboration.

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?

Given the single optional parameter, complete schema coverage, and no output schema (returns an image), the description covers the essential usage. It explains how the result is displayed ('shown inline'). It could mention what happens if the diff is empty, but the overall completeness is high for a straightforward tool.

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?

The only parameter (checkpoint) is described in the schema as 'A checkpoint commit sha', with 100% schema coverage. The description adds meaningful context: where to obtain the sha (preview History panel) and the behavior when omitted (shows current uncommitted changes), improving usability beyond the schema alone.

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 it 'Render a side-by-side git diff as an image', specifying a concrete verb and resource. It distinguishes itself from siblings by indicating it returns a visual picture, not text, and defaults to uncommitted changes.

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 when the user asks to SEE a diff visually', providing clear guidance on when to invoke. It also explains the default behavior (current uncommitted changes) and the parameter for a specific checkpoint. However, it does not explicitly mention when not to use it or alternative tools for text diffs.

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