Lists all symbols such as classes, methods, and types in a file with line numbers so you can read_file only the needed sections, or maps a directory into a repository overview for navigation.
All symbols (functions, classes, methods, types) of a file with line numbers, so you can read_file just the part you need. A directory gives a repo map of it.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes |
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. The description adds valuable behavioral detail the annotations can't: it returns symbols with line numbers and switches behavior between file and directory inputs. It leaves pagination/limits unstated, but for a simple read tool that is minor.
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?
Two tight sentences with zero waste. The primary behavior (file symbols with line numbers) is front-loaded, followed by the directory variant and the motivating use case.
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 single-parameter, read-only tool with no output schema, the description conveys what is returned, how it varies by input type, and why it's useful. Only minor gaps remain, such as output size or ordering guarantees.
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 coverage is 0% for the single 'path' parameter, so the description carries the burden and does so meaningfully: it clarifies that path may be a file (returns symbols) or a directory (returns a repo map). This is a real semantic clarification beyond the bare schema type.
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?
States a specific verb and resource: enumerating all symbols (functions, classes, methods, types) of a file with line numbers. It also describes the directory mode. It is clear, but it doesn't explicitly differentiate itself from siblings like repo_map, find_symbol, or lsp_symbols, which overlap in purpose.
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?
'so you can read_file just the part you need' implies a use case and a follow-up workflow, which is helpful context. However, there is no explicit guidance on when to choose this over find_symbol, repo_map, or lsp_symbols, and no when-not conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.