get_diff

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 describes what the tool returns ('code differences showing what lines were added, removed, or modified') and the purpose of those differences. However, it doesn't mention important behavioral aspects like whether this is a read-only operation (implied but not stated), potential rate limits, authentication requirements, or what format the diff is returned in (unified diff, JSON, etc.).

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 efficiently structured with two sentences. The first sentence states the core purpose, and the second provides usage context. Every sentence earns its place by adding value - no redundant or vague language. It's appropriately sized for a tool with 5 parameters and good schema documentation.

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 5 parameters, 100% schema coverage, but no annotations and no output schema, the description is adequate but has gaps. It explains the purpose and usage context well, but doesn't address the output format or behavioral constraints that would be important for an agent to use this tool effectively. The absence of output schema means the description should ideally mention what format the diff is returned in.

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 schema already documents all 5 parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. It mentions 'diff' generally but doesn't explain how parameters like contextLines or maxLinesPerFile affect the output format. Baseline 3 is appropriate when the schema does the heavy lifting.

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's purpose with specific verbs ('retrieve', 'show') and resource ('code differences for a pull request'). It distinguishes this tool from siblings like get_pull_request (which likely returns metadata) or get_file_content (which retrieves file contents rather than diffs). The description explicitly mentions what the diff shows: 'lines were added, removed, or modified'.

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 provides clear context for when to use this tool: 'to understand the scope of changes, review specific code modifications, or analyze the impact of proposed changes before merging.' This gives the agent specific scenarios for invocation. However, it doesn't explicitly state when NOT to use this tool or mention alternatives like get_pull_request for high-level information.

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