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

No annotations are provided, so the description carries the full behavioral-transparency burden. It discloses the return format (short summary + matching logcat lines, newest last), the filter sources, and the semantic meaning of an empty result. It does not detail rate limits, time-window semantics of 'recent', or whether it mutates state, but as a read-only diagnostic it is well covered given no annotations exist.

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?

Three sentences that each earn their place: purpose+timing, filter details, and interpretation of empty result. Slightly dense with technical detail in the filter clause, but no wasted words. It is effective and front-loaded; could arguably be trimmed but the density serves the diagnostic use case.

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 read-only diagnostic tool with 2 params (100% schema coverage) and no output schema, the description thoroughly covers what the agent needs: when to invoke, what filters are applied, expected return shape, and how to interpret both populated and empty results. The completeness is high for its complexity class—every decision point the agent might face is addressed.

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% (both udid and max are documented in the schema). The description adds behavior for max ('Newest last') which the schema already states, and clarifies output ordering but not much beyond the schema. The description restates the 'newest last' ordering for the return rather than adding new parameter meaning, so baseline 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?

Description states a clear purpose: 'Read recent Android focus-change events from logcat' with a specific verb (Read), resource (logcat focus events), and scope (recent). It names concrete log sources (ViewRootImpl, WindowManager, InputMethodManager). Although there are no direct siblings doing logcat focus reads, the description differentiates from device_type and device_tap by explicitly positioning it as the diagnostic step between tap and type.

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?

Exceptionally clear usage guidance: specifies exactly WHEN to use it ('AFTER a tap on an input field and BEFORE device_type'), names the race condition it diagnoses ('type went into the wrong field'), and explains how to interpret the result (empty result = tap did NOT change focus; lists two specific failure modes: missed tap or non-focusable element). This goes beyond 'when to use' into 'how to interpret outcomes', which is excellent.

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