List ROS2 packages in the workspace, optionally filtered by group (the top-level src// directory a package lives under — this varies by workspace, e.g. "vendor"/"description" for one repo, something else entirely for another), a finer-grained subgroup within it, or a case-insensitive substring of the package name. Call list_groups first to see the actual group/subgroup values present in this workspace.

List every group and, within each, the subgroups actually present in this workspace. By default these are derived generically from the src/ directory layout (group = first path segment, subgroup = the next one); a workspace can opt into richer classification via an optional .rosgraph-mcp.toml at its root (see the README). Call this before using subgroup filters on list_packages/the dashboard to see valid values.

Get a package's dependencies (from package.xml) and, conversely, which packages depend on it. depend_types filters to a subset of depend/build_depend/exec_depend/test_depend/buildtool_depend (default: all). transitive=True walks the full dependency closure instead of one hop.

Rebuild the package index cache for a workspace by re-scanning all package.xml files under it. Call this after pulling new source or after vcs import changes the set of packages — the index is not auto-refreshed on every tool call for performance reasons.