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

Annotations already cover the safety profile (readOnlyHint=false, openWorld, non-idempotent, non-destructive). The description adds genuinely useful behavior beyond that: it returns as soon as Siri has accepted the request rather than the answer, and an active session is required (auto-starts if needed). It doesn't mention failure modes or rate limits, so 4.

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?

Front-loaded with the core action and parenthetical examples, then follow-up guidance, then device/session caveats. Every sentence carries information, though the multi-clause structure is slightly dense for its length.

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?

Covers everything an agent needs for a 2-param, no-output-schema tool: input style, device scope, asynchronous return semantics, required session, and the downstream step to read the answer. Nothing essential is missing.

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% and both parameters are documented (text as 'What to ask Siri, as you would say it', udid). The description adds spoken-style examples ('set a timer for 5 minutes') that clarify the expected input format, but this is marginal against an already-complete schema — baseline 3.

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 (ask) and resource (Siri on iOS/Apple TV) plus the crucial mechanism — text input standing in for speech. It clearly distinguishes itself from screen/input siblings like ios_tap_by_label or ios_send_keys by naming the Siri conduit explicitly.

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?

Gives a strong when-to-use rationale ('nobody can speak to the device microphone remotely') and prescribes the follow-up workflow (screenshot ios_mjpeg_screenshot / ios_fast_screenshot a second or two later). It does not explicitly state when NOT to use it or name a competing input tool, so it stops just short of 5.

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