lxDIG MCP

test_select

Select tests affected by file changes using direct, transitive, or full mode to ensure targeted test execution.

Instructions

Select tests affected by changed files

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "changedFiles": "<changedFiles>"
    },
    "name": "test_select"
  }
}

Input Schema

Name	Required	Description	Default
`changedFiles`	Yes	Files that changed
`mode`	No	Selection mode	transitive

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.1Jun 21, 2026

TDQS

B3.4/5.0

Behavior2/5

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

No annotations are provided, so the description must carry the full burden of disclosing behavior. It only states 'Select tests' without indicating if this is a read-only operation, what side effects exist, or how the selection algorithm works (e.g., dependency analysis). The parameter 'mode' suggests different behaviors, but the description does not explain them.

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

Conciseness5/5

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

The description is a single sentence that is front-loaded and contains no extraneous information. It is appropriately concise for the tool's simplicity.

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?

Given the lack of output schema and the presence of related sibling tools, the description is incomplete. It does not specify the return format (e.g., list of test names, set of files), nor how it integrates with other tools like 'test_run'. The description is minimal, leaving agents to infer essential details.

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% with both parameters having descriptions. The description adds no new semantics beyond the schema; it merely restates the overall purpose. For high coverage, a baseline of 3 is appropriate.

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

Purpose5/5

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

The description clearly states the tool's purpose with a specific verb ('Select') and resource ('tests affected by changed files'). This differentiates it from sibling tools like 'test_run' (runs tests) and 'test_categorize' (categorizes tests).

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

Usage Guidelines3/5

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

The description implies usage when there are changed files and the user wants to determine which tests are affected, but it does not explicitly state when to use this tool versus alternatives like 'suggest_tests' or 'impact_analyze'. No exclusions or context are provided.

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