extract_variable

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

With no annotations provided, the description carries the full burden of disclosure. It states that the tool returns text edits (not applying them) and uses zero-based coordinates, and requires load_project. It adequately communicates the non-destructive, edit-returning behavior.

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: four sentences covering purpose, output, usage, and prerequisite. Every sentence adds value without redundancy, and the structure is front-loaded with the core action.

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 tool's complexity as a refactoring operation and the lack of an output schema, the description adequately explains what it does (extracts to variable), what it returns (text edits), the coordinate system (zero-based), and the prerequisite (load_project). No critical gaps are present.

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 input schema has 100% description coverage. The description reinforces the use of zero-based coordinates and aligns with parameters (start and end positions). It adds meaning beyond the schema by highlighting the zero-based requirement and the optional variableName parameter.

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 explicitly states the tool's purpose: 'Extract an expression at the given position into a local variable.' It specifies the verb 'Extract' and the resource 'expression into a local variable,' clearly distinguishing it from sibling tools like extract_constant and extract_method.

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 usage guidelines: 'Select expression by providing start and end positions' and 'Requires load_project to be called first.' It implies when to use (extracting to a local variable) but does not explicitly exclude alternatives or mention when not to use.

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