lsp_definitionFinds definition locations for an identifier at a zero-based LSP position, enabling code navigation across JavaScript, TypeScript, TSX, Python, and Rust files.
Return definition locations for the identifier at a zero-based LSP position.
| Name | Required | Description | Default |
|---|---|---|---|
| line | Yes | ||
| path | Yes | ||
| paths | No | ||
| character | Yes |
Changes observed during successful MCP inspections.
v1.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden, and it does almost none of it. It implies a read operation via 'Return', but says nothing about whether an LSP server must be running, what happens when no definition exists, or what the returned locations contain.
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?
A single front-loaded sentence with no filler; the essential information (verb, result, coordinate convention) comes first and nothing is wasted.
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?
With no output schema and no annotations, the description should explain the shape of returned locations (URI + range) and the live-LSP requirement, and it should disambiguate against find_definition/find_indexed_definition. It also leaves one of four parameters (paths) undocumented, so it is not sufficient for correct invocation.
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% for 4 parameters, yet the sentence does add real meaning: it clarifies that line/character are a zero-based position and that they locate an identifier in a file. It does not explain the 'paths' array parameter or its relationship to the singular 'path', leaving a genuine gap at low coverage.
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 gives a specific verb ('Return definition locations') and resource ('identifier') and even pins down the coordinate semantics ('zero-based LSP position'). However, it does not differentiate itself from the closely related siblings find_definition and find_indexed_definition, so an agent cannot tell from the text alone which lookup path this one uses.
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?
There is no when-to-use or when-not-to-use statement, and the crowded sibling list (find_definition, find_indexed_definition, lsp_references) makes routing ambiguous. The 'zero-based LSP position' phrasing only faintly implies live-server usage; no prerequisite (e.g. an initialized LSP session) is stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.