open_link

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

No annotations provided, so description carries full burden. Discloses fallback to default browser, error returns 'is not installed', and that browsers are recognized but not necessarily installed. Could mention return format (success/failure) but error handling is well covered.

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?

Front-loaded with purpose, followed by critical usage note, browser list, and error guidance. Slightly long (150 words) due to enumerated browsers, but each part adds value. Structure is logical.

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 side-effect action with multiple browsers and profiles, the description is comprehensive: covers parameter semantics, error recovery, prerequisites (list_installed_browsers, list_browser_profiles). No output schema, but sufficient for correct 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 100% (baseline 3). Description adds value: clarifies browser is REQUIRED when user names a browser, explains profileId format (bundleId:directory), and that profileId can infer browser if browser omitted.

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?

Clearly states the verb 'Open', resource 'URL', and scope: in a specific browser, profile, or default. Distinguishes from siblings like add_link (adds link to space) and list_installed_browsers (listing).

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?

Explicitly says when to set browser/profileId: 'if the user names a browser, you MUST set the browser (and profileId) parameter'. Provides error recovery: call list_installed_browsers on 'is not installed' error. Recommends calling list_browser_profiles first for profile-specific usage.

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