open_url

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

No annotations are present, and the description offers no behavioral details—such as whether the URL opens in a default browser, error handling, or side effects. The description fails to disclose any traits beyond the basic action.

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 a single sentence, but it is overly terse. While it is front-loaded, it omits important context, making it less effective than a slightly longer but more informative description.

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?

Given the lack of output schema and annotations, the description should compensate with details about behavior, prerequisites (e.g., device must be booted), or return values. It does not provide enough completeness for reliable invocation.

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% with clear parameter descriptions ('Device unique identifier', 'URL to open'). The description adds no extra meaning beyond what the schema already provides, meeting the baseline for high coverage.

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 'Open URL in device' uses a specific verb ('Open') and resource ('URL') targeting a device, clearly distinguishing it from sibling tools like launch_app or install_app that perform different actions.

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?

No guidance provided on when to use this tool versus alternatives such as launch_app or other device tools. The absence of context for selection criteria makes it harder for an agent to decide correctly.

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