safari_open_tab

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the genuinely useful auth context 'permissions: automation:Safari,' but omits the human-approval flow implied by the required _approvalId parameter and says nothing about tab focus or existing-tab behavior.

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?

Two short clauses, front-loaded with the action and resource; nothing is wasted. The bracketed version/permission tag is mildly noisy but also carries the one substantive extra fact.

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?

An output schema exists, so return values need no explanation, and all three parameters are fully documented in the schema. The description supplies the required-permission context; only the approval-gated write flow is left implicit.

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 documents url, _approvalId, and _idempotencyKey in detail. The description adds nothing about parameter syntax, formats, or edge cases, which is the baseline 3 when the schema does the heavy lifting.

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 and resource: 'Open one HTTP(S) URL in Safari,' with the 'one' scope constraint making it clear this is a single-tab open. It does not, however, distinguish itself from the sibling system_open_url or safari_list_tabs, which an agent must infer from names alone.

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?

There is no when-to-use guidance, no prerequisites, and no mention of when an alternative (e.g., system_open_url or web_fetch) would be preferable. Usage is only implied by the tool name.

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