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

No annotations are present, so the description carries the behavioral burden. It discloses the input mechanism, event type, coordinate space, and the 'no HID available' failure on iOS 17.x/no-tunnel. Missing minor edge-case behavior, but strong coverage overall.

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 compact sentences with no filler. The key action is front-loaded, and the pairing and compatibility caveat are delivered efficiently.

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 simple release action, the description plus fully documented schema gives enough to call the tool correctly: event semantics, pairing, coordinate meaning, and known failure condition. No output schema exists, but the main error return is disclosed.

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%, so the schema already documents all parameters. The description adds only a repeated statement that coordinates are iOS screen points and does not meaningfully extend parameter understanding 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?

States a specific verb and resource: 'Lift the held contact at (x,y) via direct HID input' with event semantics 'mouse-button-up / touch-up.' Explicitly pairs with ios_contact_hid, which distinguishes it from sibling HID gesture tools.

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?

Clearly implies the use case by pairing with ios_contact_hid and noting 'no automation session needed.' It gives good context but does not explicitly state when to prefer this over alternatives or when not to use it.

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