keyboard_snapshot

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

With no annotations, the description carries the full behavioral disclosure burden. It does this well by noting that the first call builds and starts cached XCTest support while later calls reuse the simulator session, alerting the agent to an initialization cost and stateful behavior. It does not go into failure modes or permissions, but the core behavioral traits are disclosed.

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 short, purposeful sentences. The primary purpose is front-loaded, and the second sentence supplies only essential usage and behavioral context. No filler or redundant restatement of the tool name appears.

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 provides the key prerequisite, the first-call initialization behavior, and the output type, with an output schema covering return value structure. The main gap is the lack of parameter documentation, but the parameter names and output schema give an agent enough to invoke the tool correctly in most cases.

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 0%, so the description must compensate, but it never mentions any of the three parameters. In particular, the 'raw' boolean flag has no explanation, and while simulator_id and extension_bundle_id are somewhat self-explanatory, their exact expected formats or relationship to the tool's behavior are left unspecified.

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 opens with a specific verb and resource: 'Return the active keyboard extension accessibility tree and tap coordinates.' This clearly distinguishes the tool's purpose from a generic snapshot or screenshot utility, even without sibling tools to compare against.

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 gives an explicit precondition: the client app must already be foreground with a focused text field presenting the requested extension. It does not name alternatives or exclusions, but with no sibling tools listed, this level of context is sufficient for an agent to know when calling is appropriate.

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