lxDIG MCP

semantic_slice

Retrieve exact source lines for a symbol or file, with optional dependency and memory context.

Instructions

Return relevant exact source lines with optional dependency and memory context

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "semantic_slice"
  }
}

Input Schema

Name	Required	Description	Default
`file`	No	Relative or absolute source file path
`symbol`	No	Symbol id/name (e.g. ToolHandlers.callTool)
`query`	No	Natural-language fallback query
`context`	No	Slice detail mode	body
`pprScore`	No	Optional PPR score from context_pack pipeline
`profile`	No	Response profile	compact

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.1Jun 21, 2026

TDQS

C2.9/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. It mentions optional dependency and memory context but does not disclose side effects, read-only nature, or prerequisites. Agents lack critical behavioral cues.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence with key information front-loaded. No waste, but the phrasing 'relevant exact source lines' is somewhat vague. Still concise overall.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With 6 optional parameters including enums for context and profile, and no output schema, the description is too brief. It does not explain modes like 'signature', 'body', 'with-deps', 'full', or the profile options, leaving agents underinformed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so schema already documents parameters. The description adds minimal extra meaning beyond 'optional dependency and memory context'. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Describes returning exact source lines with optional context, clear verb+resource. However, it does not explicitly differentiate from siblings like semantic_search or code_explain, missing a chance to improve selection.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool over alternatives. With many sibling tools dealing with code, the absence of usage context is a significant gap.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.