sim_list

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

No annotations are provided, so the description must carry the behavioral burden. It says it returns raw simctl JSON, which implies a read-only operation, but it doesn't explicitly state that it has no side effects or mention any authentication/SSH requirements (host, user). The verb 'List' suggests non-destructive behavior, but this is not stated outright.

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?

Two sentences, front-loaded with the purpose and underlying command, and it includes the filter option. No fluff or redundant information.

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?

The description covers the return format (raw simctl JSON) and the booted_only filter, but it omits critical details about required parameters (host, user) and optional key_path. Since an output schema exists, the return structure is likely documented there, but the input parameters are not adequately explained.

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 description only explains booted_only, while the schema has four parameters including required host and user. With schema description coverage at 0%, the description fails to document the majority of parameters, leaving the agent to guess what host and user mean (likely SSH connection info) and what key_path is for.

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 it lists iOS simulators on the Mac using xcrun simctl, and distinguishes it from sibling sim_* tools (boot, install, launch, etc.) by being a pure list operation. The verb 'List' plus the resource 'iOS simulators' 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?

It explains the intended use case (picking UDIDs, runtime versions, names) and mentions the booted_only filter to narrow results. It doesn't explicitly state when not to use it or point to alternatives, but the sibling tools are obviously different actions, and the description implies this is the go-to for listing.

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