List systemd Services

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful context beyond annotations: pagination metadata (total, has_more, next_offset), the return fields (unit name, active/sub state, description), and the state filter behavior. This provides a clearer picture of the tool's operational characteristics.

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 well-structured with a concise opening sentence, a clear Args list, a Returns line, and an example. While it duplicates schema details, the structure makes it easy to scan and the example is valuable. It is appropriately sized for the tool's complexity.

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?

Given the presence of an output schema, the description need not explain return values in depth, but it still provides a useful summary and pagination metadata. It also includes a practical example and references to related tools. The description is complete for a read-only list tool, covering parameters, output, and usage context.

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%, so the schema already documents all parameters and defaults. The description repeats the parameter list but adds marginal value by cross-referencing ubuntu_list_servers for the server parameter and providing a usage example. It does not materially enrich parameter meaning beyond what the schema provides.

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's function: 'List systemd services on an Ubuntu server, optionally filtered by state.' The verb 'List' and resource 'systemd services' are specific, and the optional filtering distinguishes it from sibling tools like ubuntu_service_status, which likely targets a single service.

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 provides a clear example ('state='failed' answers "is anything broken on web-01?"') and references the prerequisite source for the server parameter (ubuntu_list_servers). However, it does not explicitly mention when not to use this tool or alternatives like ubuntu_service_status for individual service details, so it lacks full exclusion guidance.

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