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

Annotations already declare this is non-read-only, non-destructive, non-idempotent, and not open-world. The description adds valuable behavioral context beyond that: the URL is short-lived (~5 minutes), single-device, and requires no login or session for the viewer. It does not explain what the non-read-only side effect is, which is a minor remaining gap.

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 tight sentences, front-loaded with the core action and output, followed by the key contrast and usage condition. Every sentence carries distinct information with no repetition.

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?

With a single required parameter and no output schema, the description fully covers what the tool returns (a viewer URL), how to use it (open directly, no login/session), and its lifetime. Nothing essential for correct invocation 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 there is only one parameter, 'udid', already documented as 'iOS device UDID.' The description adds no extra syntax or format details beyond the schema, so the baseline score of 3 applies.

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 states a specific verb and resource: 'Get a LIVE video-stream link for an iOS device.' It explicitly distinguishes this tool from ios_screenshot ('unlike ios_screenshot, which is one frame') and makes the iOS scope unambiguous.

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 an explicit when-to-use condition: 'Use this to let a person supervise what the agent is doing on the device.' It also names the alternative use case via the ios_screenshot contrast, so an agent can choose correctly between live viewing and a single frame.

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