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

Annotations already cover the safety profile (idempotent, non-destructive, not read-only), and the description adds genuine behavioral context beyond them: the paste injection is built into the device control protocol rather than requiring a separate Ctrl+V, and an empty string clears the clipboard. It stops short of noting auth, device-state, or failure 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?

Three short sentences, front-loaded with the core action, then the paste side effect, then the clearing edge case. Zero filler and no repetition of schema content beyond what reinforces 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 three-parameter setter with no output schema, the description covers the action, the notable side effect, and the edge case, which is nearly everything an agent needs. It could still mention required device state (unlocked/focused target for paste) to be fully self-sufficient.

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 coverage is 100%, so baseline is 3, but the description adds real semantics the schema doesn't: paste triggers KEYCODE_PASTE 'immediately after' the set, and that this happens inside the control protocol. The empty-string-clears behavior duplicates the schema's content description but confirms the edge case.

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?

States a specific verb and resource ('Set the Android device clipboard') along with the transport ('device control channel'), so the operation is unambiguous. It doesn't explicitly contrast itself with the obvious counterpart device_clipboard_get or the iOS ios_clipboard_set_hid, but the Android-specific scope is clear enough to disambiguate.

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?

Usage is implied rather than stated: the agent learns that paste:true triggers an immediate KEYCODE_PASTE, which suggests the tool is for clipboard-then-paste workflows. There is no explicit when-to-use vs. alternatives guidance, no mention of prerequisites (device unlocked, focused field), and no pointer to device_clipboard_get for the read counterpart.

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