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

With no annotations provided, the description carries the full burden and does so admirably. It discloses the conditional behavior (in-place navigation vs. cold-open), states that it verifies the resulting URL and never silently no-ops, and explains the side effect of making the landed page the current page for subsequent ios_safari calls.

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 but every sentence earns its place, covering purpose, conditional behavior, prerequisites, return contract, and downstream tool context. It is front-loaded with the core action and packs significant operational nuance without becoming unstructured.

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?

There is no output schema, but the description clearly enumerates the return fields { navigated, requestedUrl, finalUrl, pageId, method }. It also covers prerequisite setup, pageId usage, subsequent tool calls, and when a list_pages round trip is unnecessary, making it highly complete for agent 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 description coverage is 100%, so the schema already fully documents all four parameters. The description reinforces pageId semantics but adds little parameter-level meaning beyond what the schema already states, keeping this at the baseline score.

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: 'Navigate Safari to a URL on an iOS device.' It also differentiates itself from the sibling ios_navigate_url by explicitly saying 'Prefer this over ios_navigate_url for Safari,' making the tool's scope unmistakable.

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?

The description gives explicit when-to-use guidance: use it for Safari navigation, prefer it over ios_navigate_url for Safari, and it explains the two operational modes (active tab navigation vs. cold-open). It also mentions the required Remote Automation setting, giving concrete context for correct invocation.

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