Locate the definition of a code symbol by providing its file, line, and character position.
Definition location of the symbol at a position.
| Name | Required | Description | Default |
|---|---|---|---|
| file | Yes | Absolute file path | |
| line | Yes | 1-based line | |
| character | Yes | 1-based column |
Changes observed during successful MCP inspections.
v3.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered structurally. The description adds nothing beyond that: no note on what is returned, whether the definition may be in another file, or behavior when no definition exists.
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 short sentence with no waste, and the operative concept (definition location of the symbol) is front-loaded. It is terse to the point of being slightly under-specified rather than verbose.
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 simple, fully-schema-documented, read-only navigation tool, the description is minimally sufficient. It omits any handling of the no-definition case and does not clarify its relationship to the overlapping lsp_definition sibling.
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%, with clear notes that file is absolute and line/character are 1-based. The description adds no syntax or format detail beyond the schema, so the baseline 3 applies.
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 names the specific resource (definition location of the symbol) and the positioning input, so an agent knows this resolves a symbol to its definition. However, it is stated as a noun phrase rather than a verb, and it does not differentiate itself from the sibling lsp_definition, which appears to do the same thing.
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 guidance and no alternatives named, despite the presence of lsp_definition among siblings that likely overlaps in function. The agent must infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.