Retrieve a line-bounded, sanitized snippet from an allowed file while enforcing path controls and redacting PII before it reaches an LLM.
Retrieves a line-bounded, sanitized snippet from an allowed file.
| Name | Required | Description | Default |
|---|---|---|---|
| lineCount | No | Number of lines to read (capped at max_snippet_lines) | |
| startLine | No | Start line number (1-indexed) | |
| relativePath | Yes | Relative file path |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose two meaningful traits beyond the schema: output is 'sanitized' and reads are restricted to 'allowed' files. However, it says nothing about what happens for a disallowed path, error behavior, or what gets stripped during sanitization.
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; every phrase (line-bounded, sanitized, allowed file) carries information. It is arguably under-sized for the behavioral quirks it hints at, keeping it just short of a 5.
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 3-parameter read tool with no output schema and no annotations, the description covers the basics but leaves key questions open: what 'allowed' means, whether sanitization alters content, and how errors surface. Adequate but with clear gaps.
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%, so all three parameters (relativePath, startLine, lineCount) are already documented. The description's 'line-bounded' wording reinforces the line-range parameters but adds no format or default details beyond the schema; 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?
States a specific verb and resource ('Retrieves ... snippet') plus three qualifiers: line-bounded, sanitized, and from an allowed file. An agent can tell it reads file content, but nothing in the text distinguishes it from siblings list_structure or search_docs.
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 or when-not-to-use guidance, and no mention of alternatives such as search_docs. The only implicit cue is that the tool returns file content, leaving routing decisions to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.