List running applications

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

Annotations declare readOnlyHint, idempotentHint, and destructiveHint=false, which already communicate that this is a safe, non-mutating operation. The description adds context by specifying the data source (System Events) and clarifying that includeBackground includes agents, which goes beyond the annotation's generic safety profile. No contradictions with annotations.

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 two concise sentences, with the primary purpose front-loaded in the first sentence and the parameter effect in the second. Every word earns its place—no filler. It is easy to parse quickly.

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 list tool with a single optional parameter and no output schema, the description is sufficient. It states what is returned (name, pid, visible) and explains the parameter's effect. The annotations cover safety, and the simple nature of the tool means no additional context is required. Nothing critical is missing.

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 100%, so the schema already documents the includeBackground parameter. The description adds a specific clarification that includeBackground includes agents, which refines the schema's description of 'all processes' and helps the agent understand the parameter's effect in the macOS context. This is a modest but useful addition.

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 identifies the tool as listing foreground macOS application processes from System Events, specifying the captured fields (name, pid, visible). It distinguishes itself from sibling tools like get_system_info or list_roots by focusing specifically on running applications. The inclusion of the source makes the purpose 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?

The description does not explicitly state when to use this tool over alternatives. It provides no exclusions or guidance on when not to use it. While the purpose is clear, there's no routing to other tools such as get_system_stats or get_system_info, leaving the agent to infer when this list of applications is the right choice.

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