sim_screenshot_hires

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

With no annotations, the description carries the full burden for behavioral disclosure. It discloses the key trait of being full-resolution and lossless, and contrasts with the downscaling behavior of the proxy tool. However, it does not mention any prerequisites (e.g., booted simulator) or side effects, but for a read-only screenshot tool this is largely sufficient.

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 concise sentences. The first states the core function, the second provides usage context and a comparison. No wasted words, front-loaded with the key 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?

Despite no annotations and no output schema, the description is complete for this tool's complexity. It explains the output (PNG file), the method (simctl), the difference from the sibling tool, and when to use it. The optional parameters and defaults are documented in the schema, so the description covers all essential 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 baseline is 3. The description does not add extra meaning about the parameters beyond what the schema provides, but it does implicitly reference simulator context ('via simctl'). Since the schema already fully documents both parameters, a score of 3 is appropriate.

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 produces a 'Full-resolution lossless PNG via simctl, with dimensions', which specifies both the verb (capture) and the resource (simulator screenshot). It explicitly distinguishes from the sibling 'screenshot' tool by noting the downscaling limitation, providing clear differentiation.

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?

Provides explicit guidance on when to use: 'Use for any pixel, spacing or colour question'. It also names the alternative ('The proxied screenshot tool') and explains why it is unsuitable for visual QA, giving a clear when-to-use and when-not-to-use directive.

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