open_permission_settings

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

Annotations already declare it is not read-only, not destructive, and idempotent, so the safety bar is lower. The description adds real context beyond them: it opens the OS Settings app and a Finder window, requires the user to drag Timbre into the list and toggle it, and notes the permission then takes effect by itself without a further tool call. It does not warn about macOS-version differences or what the call returns if the pane is already open.

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 sentences, each covering one mode, with the failure condition front-loaded before the action. The clause 'so the user only drags it into the list and switches it on' is slightly long but earns its place by setting the user's expectation of manual follow-up.

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 one-parameter toggle tool with no output schema, the description covers both modes, the triggering failure, and the post-call outcome. No annotations or schema fields are left unexplained, and an agent needs nothing else to decide whether and how to call it.

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%, so the schema already defines the single 'pane' parameter and its default. The description goes further by explaining what each value actually does — full_disk_access selects the app in Finder for dragging, automation targets the Automation pane after macOS blocked Mail control — which is meaning beyond the enum strings.

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 names a concrete verb and target: it opens System Settings at Full Disk Access and selects Timbre in Finder, and it distinguishes a second mode (Automation). An agent can tell this apart from every sibling tool (create_draft, read_mail, mail_status, etc.) without opening the schema, since none of them touch macOS settings.

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?

It gives explicit triggers for both modes: 'When Timbre cannot read Mail yet' for full_disk_access and 'when macOS did not let Timbre act in Mail' for automation. What is missing is any when-NOT guidance or a named alternative to try first, so the routing is clear but not complete.

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