ACTION_DYNAMIC_ISLAND

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

With no annotations supplied, the description carries the full burden and does so well: it discloses the overlay-permission prerequisite, that failure without permission is silent and writes no variables, that execution is non-blocking, and that the result is a variable-snapshot JSON. It also flags the duration_ms type trap (string values are ignored and fall back to 3000), which is exactly the kind of behavior an agent could not guess.

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 purpose is front-loaded in the first clause, and every later sentence carries operational value (permission, non-blocking, type gotcha, interpolation). Minor deductions for a stray doubled period ('。。') and for mixing parameter-level detail into the prose body.

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?

There is no output schema, and the description compensates by stating that the result comes back as a variable snapshot JSON. Permission requirements, failure semantics, blocking behavior, and the key parameter pitfall are all covered, which is enough for an agent to call a 5-parameter, 1-required tool correctly.

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 the baseline is 3, but the description adds meaning the schema does not: duration_ms must be a numeric literal or it is silently replaced by 3000, and string parameters accept ${var} interpolation. require, on_error, and node_timeout_ms are only covered by their schema text.

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 names a specific verb and resource: it pops up a Dynamic Island style capsule at the top of the screen and auto-dismisses. That is concretely distinct from a generic notification. It never distinguishes itself from near-identical siblings such as ACTION_TOAST or ACTION_SEND_NOTIFICATION, so an agent must infer which popup tool to pick.

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 only implied through behavioral facts: it is non-blocking, so the next node runs immediately, and it requires host-app registration plus overlay permission. There is no explicit when-to-use or when-not-to-use guidance, and no sibling is named (ACTION_TOAST, ACTION_SEND_NOTIFICATION, ACTION_MINI_SCREEN are the obvious alternatives).

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