get_simulator_screenshot

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

The annotations provide readOnlyHint=true, so the agent knows it's a safe read operation. The description adds no additional context such as output format, platform nuances, or side effects. Moreover, the reference to 'iOS simulator' conflicts with the schema's support for Android, misrepresenting the tool's behavior.

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, short sentence, making it easy to read. However, it includes the inaccurate 'iOS' qualifier, which reduces precision despite its brevity.

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 tool with two parameters and no output schema, the description is too minimal. It doesn't mention that the platform parameter can be 'android', nor does it describe what the screenshot output looks like (e.g., file path, base64). The readOnly annotation covers safety but not functional completeness.

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 100% coverage with descriptive comments for both deviceId and platform, including an enum. The tool description adds no extra parameter meaning, so the baseline 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 uses a specific verb 'Get' and resource 'screenshot', and it clearly differs from sibling tools like get_simulator_list. However, it inaccurately limits the tool to 'iOS simulator' when the schema explicitly supports both iOS and Android, making the purpose slightly misleading.

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?

There is no guidance on when to use this tool or how it relates to alternatives like get_simulator_list or check_supported_platforms. The description only states what it does, leaving the agent to infer when it should be invoked.

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