get_annotated_source
Returns the source file content annotated line-by-line with coverage status ([COVERED], [NOT COV], [NO DATA]). Provides the full picture so the agent can understand the logic around uncovered regions.
LABSCO SUMMARY
The third tool is what changes an agent's relationship with coverage: the uncovered lines arrive with the code around them.
A percentage says a file needs tests and a list of line numbers says where, but neither says what the untested branch does. get_annotated_source marks each line COVERED, NOT COV or NO DATA across a range, which puts the gap and its surrounding logic in front of the model together. NO DATA is worth reading as its own state rather than as zero, since it marks lines the report says nothing about. The merging inside list_uncovered_regions is what keeps this workable — ranges rather than a column of individual line numbers.
What it is
A coverage reader with three tools over an lcov file — aggregated and per-file statistics, uncovered regions for one file, and source annotated with per-line coverage status.
What you get
- get_coverage_overview returns aggregated and per-file line, function and branch percentages, with a directory filter, a sort order and a threshold for prioritising.
- list_uncovered_regions returns the uncovered lines and branches for one file, merging consecutive uncovered lines into startLine and endLine ranges.
- get_annotated_source returns the file's source annotated line by line as COVERED, NOT COV or NO DATA, over a line range you choose.
Requirements
An lcov report and the project root it was generated against — lcov_path and project_root are parameters on all three tools, with additional_roots and source_root for source that sits elsewhere.
Setup effort
One command — npx -y @sofia-open-source/analyze-coverage-mcp
USE CASES
01
Finding which files are worth writing tests for first
A directory filter and a threshold turn a whole-project report into a shortlist, sorted by whichever coverage dimension matters.
02
Pinpointing exactly what is untested in one file
Consecutive uncovered lines come back as ranges rather than as a column of numbers, which is what makes the list readable.
03
Writing a test for a branch you have to understand first
The annotated source shows the uncovered lines inside the logic that surrounds them, marked COVERED, NOT COV or NO DATA.
3 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
get_coverage_overview
Returns aggregated and per-file coverage statistics (lines, functions, branches %). Use this to identify files or directories with low coverage and prioritise testing efforts.
list_uncovered_regions
Returns uncovered lines and branches for a specific file. Consecutive uncovered lines are merged into ranges ({startLine, endLine}). Use this as a GPS to pinpoint exactly what code paths are missing tests.
BEFORE YOU INSTALL
What to know first
Tools you get
3 tools when we connected.
Requires
npx on PATH
CONTEXT COST
Light Standing cost
Rated by the size of the 3 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Add the block to your client, or run the command directly.
Server setup
Configuration file
JSON
{
"mcpServers": {
"analyze-coverage-mcp": {
"command": "npx",
"args": [
"-y",
"@sofia-open-source/analyze-coverage-mcp"
]
}
}
}npx
TERMINAL
npx -y @sofia-open-source/analyze-coverage-mcp
