arc-mcp

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

With no annotations provided, the description carries the full burden. It discloses the immediate action and AppleScript mechanism, but doesn't mention potential side effects, error conditions, or what happens if the space doesn't exist. It's adequate but lacks depth for a tool that interacts with external applications.

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 perfectly concise - one sentence that efficiently communicates the core functionality and key optional feature. Every word earns its place with zero waste or redundancy.

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?

Given the tool's moderate complexity (interacting with external browser via AppleScript), no annotations, and no output schema, the description is reasonably complete. It covers the main action and key optional parameter, though could benefit from more behavioral context about error handling or limitations.

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 both parameters thoroughly. The description adds minimal value by mentioning the optional space parameter but doesn't provide additional context beyond what's in the schema. Baseline 3 is appropriate when 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?

The description clearly states the specific action ('Open a URL'), the target resource ('in Arc browser'), and the mechanism ('uses AppleScript'). It distinguishes itself from siblings like 'add_tab' by specifying immediate opening in Arc rather than generic tab management.

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 implies usage when needing to open a URL in Arc browser, particularly with optional space targeting. However, it lacks explicit guidance on when to use this versus alternatives like 'add_tab' or 'focus_space', and doesn't mention prerequisites or exclusions.

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