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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it delivers substantially. It explains the internal technical reason (shell process lacks foreground/READ_CLIPBOARD_IN_BACKGROUND on 13+), and crucially discloses that it returns an 'empty-clipboard sentinel' rather than the raw OS error. This empty-sentinel behavior is a critical behavioral trait that could otherwise mislead an agent into thinking the clipboard is genuinely empty.

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, focused paragraph that front-loads the core purpose ('Read the current clipboard content') before diving into version-specific caveats. It's well-structured, and every sentence earns its place by covering purpose, OS-version differences, and the recommended workaround. Slightly dense in the middle section but appropriately so given the complexity of the cross-version behavior.

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 simple single-parameter, no-output-schema tool, the description is thorough. It covers the core operation, the version-dependent failure mode, the sentinel return value, and the mitigation strategy. It could arguably be complete at 5 for its simplicity, but the deep technical rationale (shell permissions) is perhaps more detail than strictly needed, and the fact that it reads as more iOS-comparative than necessary tempers the score slightly.

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 single parameter (udid) has 100% schema description coverage ('Device serial number (UDID)'), so the schema already fully documents it. The description adds no parameter-specific detail beyond the schema, which is acceptable given the baseline of 3 for high coverage. No additional syntax or format guidance is needed for a simple string UDID parameter.

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 what the tool does: 'Read the current clipboard content from an Android device.' It uses a specific verb (read) plus resource (clipboard content), and it distinguishes itself from the sibling device_clipboard_set by explicitly noting the 13+ blocking behavior and recommending the set-then-paste alternative. It also differentiates from the iOS clipboard tools (ios_clipboard_get_hid, ios_get_pasteboard) by specifying the Android platform.

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 provides explicit when-to-use guidance by explaining the Android version dependency: reliable on 12 and earlier, blocked on 13+. It names the specific alternative approach (device_clipboard_set for round-tripping text on 13+) and warns explicitly not to rely on read-back on 13+. This goes beyond implied usage and provides actionable context for the agent.

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