service_state

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

The description explicitly declares the tool is read-only ('never changes state') and lists the underlying systemctl commands. With no annotations provided, it sufficiently conveys behavioral safety. However, it omits potential error conditions or permission requirements.

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?

The description is concise (four sentences, no filler) and front-loaded with the primary purpose. Each sentence adds necessary information: purpose, read-only guarantee, return format, and usage context.

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 read-only tool with no output schema, the description provides the return JSON structure and its role in detection. It lacks error behavior details (e.g., missing instance) but is otherwise complete for its complexity.

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?

The input schema already covers the single parameter 'instance_id' with a clear description. The description adds 'one instance' context but offers no additional semantic meaning beyond what the schema provides, so baseline score 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?

The description clearly states the tool retrieves enablement, active, and reload states of enabled systemd services for a single instance. It uses specific verbs ('get', 'powers') and distinguishes itself from siblings like 'check_status' by focusing on systemd service state details.

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?

The description implies use for service-state detection but does not explicitly state when to use this tool versus alternatives (e.g., 'check_status' or 'get_server_info'). No exclusion criteria or when-not-to-use guidance is provided.

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