iphone_open_url

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

No annotations are provided, so the description carries the full burden. It usefully discloses that the system default handler is used and that web pages land in Safari, but says nothing about failure behavior, whether the calling app is backgrounded, or whether the device must be unlocked.

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?

A single front-loaded sentence with zero filler, and the Safari behavior is placed immediately after the core action. It is efficient but so terse that it omits information the agent needs.

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 5-parameter tool with no output schema and no annotations, the description still gives the key mental model: system-handled URL open with web content in Safari, and the schema covers the optional follow-up capture options. Only the url format contract and failure mode are 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 80%, so the schema largely documents the optional then/then_region/then_filter/then_settle chain. The description adds no meaning to the required url parameter, such as accepted formats (https:// vs shortcuts:// vs custom schemes), which is the one thing an agent could get wrong here.

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 (打开/open) and resource (链接或 URL Scheme) plus the concrete effect that web pages open in Safari. It does not explicitly distinguish itself from sibling iphone_launch_app, so it stops short of a 5.

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?

Usage is implied by naming URL/URL-Scheme as the input, which separates it loosely from app-launching siblings. There is no explicit when-to-use or when-not-to-use statement and no naming of the alternative tool (iphone_launch_app) for non-URL intents.

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