Retrieves the expected term type at the cursor position in a Lean file to guide proof construction and type checking. Use it to inspect the goal type during interactive verification.
Queries expected term type under cursor ($/lean/plainTermGoal)
| Name | Required | Description | Default |
|---|---|---|---|
| col | No | 1-based column number | |
| line | Yes | 1-based line number | |
| filePath | Yes | Absolute or relative path to the .lean file | |
| character | No | Synonym for col |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. The verb 'queries' implies a read-only operation, but nothing else is revealed—no mention of error cases, return format, or prerequisites. The tool's behavior depends on the file state, and the description offers no hints.
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, front-loaded sentence that states the purpose immediately and includes the protocol method in parentheses as supplementary info. There is no fluff or redundancy.
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 provides the core purpose but does not elaborate on return values or edge cases, and there is no output schema to fill that gap. For a simple query tool, it is minimally adequate but lacks richer context that could help an agent understand the tool's full behavior.
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 are already documented in the schema with descriptions (e.g., column is '1-based column number', line is '1-based line number'). The tool description adds no parameter-specific meaning, but with 100% schema coverage, the baseline of 3 is appropriate.
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 states a specific verb ('Queries') and a clear resource ('expected term type under cursor'), making the tool's function unambiguous. It also differentiates from siblings like lean_goal (queries goals) and lean_lookup_symbol (looks up symbols) by focusing on term type at a cursor position.
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?
No guidance is given on when to use this tool versus its siblings. The description does not mention any selection criteria, alternatives, or exclusions. An agent is left without context on when this tool is the right choice compared to lean_goal or others.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.