Retrieves source code for one symbol or line range from a file, so agents can inspect only needed code and reduce context tokens.
Source of one symbol (e.g. "fn", "Class.method") or a line range.
| Name | Required | Description | Default |
|---|---|---|---|
| file | Yes | ||
| symbol | No | ||
| endLine | No | ||
| startLine | No |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare readOnlyHint=true, so the safety profile is covered, but the description adds almost nothing beyond that. It does not say what happens if the symbol is not found, whether `symbol` overrides `startLine`/`endLine`, whether line bounds are inclusive, or how large an unbounded range response might be.
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 the key mode distinction front-loaded and no filler. However, its brevity crosses into under-specification for a 4-parameter tool, so the efficiency does not fully pay off.
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 simplicity (single-file read, no nested objects, no output schema, read-only), the description plus name plus schema is enough to attempt a call. Missing details about file targeting and mode precedence are gaps, but not blockers for a straightforward source-retrieval tool.
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%, so the description carries the full burden, yet it only clarifies `symbol` (with format examples like "Class.method") and hints at the line-range pair. It never explains `file`, whether both `startLine` and `endLine` are required together, or the precedence between the two selection modes.
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 conveys the resource (source of a symbol) and names two modes (symbol name or line range), but the verb is implicit and the required `file` target is never mentioned. It does not distinguish itself from siblings like `outline` or `search`, so an agent must infer that this fetches raw source rather than a structural listing.
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 when-to-use guidance and no exclusions. With siblings `outline`, `search`, and `summary_cache` all plausibly touching source, the description never says why to pick this one or when a symbol lookup should be preferred over a search.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.