list_services

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

With no annotations, the description carries the behavioral disclosure burden. It clearly indicates a read-only listing operation and names the underlying launchctl list command, which adds useful context. However, it does not describe output scope, default behavior when no filter is given, or whether only loaded/running services are shown.

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 extremely concise: one sentence stating the action, followed by one line documenting the single parameter. There is no redundant filler, and the most important information is front-loaded.

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 simple list tool with one optional parameter and an output schema present, the description covers the core action and parameter meaning adequately. It does not explain when to prefer this over list_plists or print_service, but the low complexity and available output schema reduce the need for additional detail.

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 coverage is 0%, so the description must compensate for the one parameter. It does so by clarifying that label_filter is an 'Optional substring filter for the service label,' adding meaningful semantic information beyond the schema's generic 'Label Filter' title.

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 uses a clear verb and resource: 'List launchd services from `launchctl list`.' It accurately conveys the tool's function and is distinct from siblings like kickstart_service or bootout_service. It does not explicitly call out differences from siblings such as print_service, but the purpose is unambiguous.

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?

No guidance is provided about when to use this tool versus alternatives like list_plists or print_service. The name and siblings imply a listing use case, but the description does not state any conditions, exclusions, or preferred selection criteria.

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