list_sims

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

With no annotations, the description carries full burden. It discloses that the tool lists devices returning udid, name, state, runtime. It does not explicitly state that the operation is read-only or non-destructive, but given the nature of listing, it is likely safe. Missing details on scope (e.g., all simulators) prevent a higher score.

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 a single, clear sentence that directly states the tool's function and output fields. No unnecessary words, and it is front-loaded with the verb 'List'. Perfect conciseness.

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 tool has no parameters, no output schema, and is a simple listing operation, the description is mostly complete. It explains what is returned (udid, name, state, runtime). A higher score would require mention of whether all simulators are returned or only those meeting certain criteria, but it is sufficient for a basic listing tool.

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 has zero parameters with 100% description coverage (empty description). The description adds no parameter details, but since there are none to explain, the baseline is 4. The tool's simplicity means no further parameter semantics are needed.

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 purpose: 'List available simulator devices'. It specifies the exact fields returned (udid, name, state, runtime), which is a specific verb+resource. It distinguishes itself from sibling tools like boot_sim or install_app by focusing on listing, not manipulation.

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?

Usage is implied: use this to see available simulators. However, there is no explicit guidance on when to use this versus other tools, such as when you need to boot a sim. Since the tool is straightforward with zero parameters, the lack of explicit guidelines is acceptable but not ideal.

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