scan_diff

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

With no annotations, the description carries the full burden of behavioral disclosure. It states that raw diff content is not echoed, which is a meaningful behavior. However, it does not describe what the tool does return, whether it is read-only, or any side effects. For a scan tool, this is a partial disclosure; more detail on the output format would improve transparency.

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 a single, focused sentence that front-loads the core purpose and the key behavioral absence. It is concise with no redundant wording. However, given the tool's parameters and lack of annotations, it may be slightly under-specified, but it earns its place as an efficient opening statement.

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 tool has three parameters, no output schema, and no annotations. The description does not explain parameter semantics, expected output, or usage context beyond the scope of a git diff. An agent would lack crucial details to invoke the tool correctly, making the description inadequate for the tool's complexity.

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 0% (no parameter descriptions), so the description must compensate. It does not mention base_ref, head_ref, or workspace_path at all. The parameter names and defaults in the schema give some hints, but the description adds no additional meaning, leaving an agent unsure how to set the refs or workspace path correctly.

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 identifies the resource (a git diff) and the action (scan), and adds a specific behavioral distinction ('without echoing raw diff content in the MCP response'). This unmistakably differentiates it from sibling scan tools like scan_workspace and scan_text, which target different resources.

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 when to use this tool (for scanning a git diff) but does not explicitly mention alternatives or exclusions. An agent can infer the primary use case, but there is no guidance on when NOT to use it versus scan_workspace or scan_text. The scope is clear enough to make an inference, so it is not a complete miss.

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