List systemd --user services and their active states, and detect failed background units. Filter to failed units only to quickly audit user-level service health.
List systemd --user services, active states, and detect failed background units.
| Name | Required | Description | Default |
|---|---|---|---|
| failed_only | No | Only return units in failed state (default: false) |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It usefully discloses the '--user' scope (user session units, not system-wide) and that it surfaces active states plus failures, implying a non-mutating read. It does not state permission requirements, whether it needs a running user systemd instance/dbus, or anything about output shape or pagination.
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?
One compact sentence with the resource front-loaded and no filler. It slightly overloads three ideas (listing, active states, failure detection) into a single clause, but nothing is wasted.
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 0-required-param read tool with no output schema and no annotations, the description is adequate: it names the resource, the scope, and the key output categories. It leaves open what the return looks like and what environment prerequisites exist, which for an unannotated system-inspection tool is a real but moderate gap.
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% and the single boolean (failed_only) is fully documented in the schema. The description's mention of failed units loosely aligns with it but adds no syntax or default information beyond the schema, so 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 (List) and resource (systemd --user services) plus what it surfaces (active states, failed units). The '--user' scope meaningfully distinguishes it from a system-wide service inspection, though it never explicitly names inspect_systemd_timers as the sibling for timer units.
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?
Usage is only implied: 'detect failed background units' hints this is for diagnosing failures, and the failed_only param reinforces that. There is no explicit when-to-use, when-not-to-use, or routing to check_system_resources / inspect_systemd_timers when a different subsystem is the actual target.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.