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

With no annotations, the description carries the full burden and does so thoroughly: touches persist until the release tool is called, each call advances one frame, all contacts land at the same instant, and the no-HID-available failure mode is disclosed. It also clarifies that no automation session is needed.

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 dense yet compact, front-loading the core action and then adding only high-value behavioral details: frame semantics, steering, release coupling, coordinate units, and the failure condition. No sentence is wasted.

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 3-parameter tool with no annotations and no output schema, the description is unusually complete: it covers the multi-touch lifecycle, repeated-call semantics, coordinate convention, and environment failure. The only minor omission is the unnamed success return value, but invocation-critical behavior is fully specified.

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 schema already documents all three parameters at 100% coverage, including norm's fraction behavior and points ordering/finger identity. The description adds the iOS screen-point coordinate unit and reinforces the five-contact limit, but it does not materially expand parameter meaning beyond the schema.

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 ('press-and-HOLD'), a concrete resource ('up to five contacts at once via direct HID input'), and the defining frame semantics: one call equals one frame with all fingers landing simultaneously. It is clearly distinct from the release sibling and from session-based automation input.

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?

It gives clear context for use: call repeatedly to steer multi-touch gestures such as a two-finger drag, and keep fingers held until ios_release_contacts_hid. It does not explicitly state alternatives or exclusions (e.g., when to prefer ios_contact_hid or other tap/drag HID tools), so it stops short of a 5.

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