arc-mcp

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states it will 'List all Arc browser spaces' but doesn't specify what 'all' means (e.g., current user's spaces, all accessible spaces), whether there are pagination limits, what format the output takes, or any error conditions. The description is minimal and lacks important operational context.

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 a single, efficient sentence that gets straight to the point with no wasted words. It's front-loaded with the core functionality and doesn't include unnecessary elaboration or redundant information.

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 simple listing tool with no parameters and no output schema, the description is adequate but minimal. It tells the agent what the tool does but lacks details about output format, scope limitations, or behavioral characteristics that would be helpful for proper invocation. Given the tool's simplicity, it's minimally viable but could provide more context.

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?

The tool has zero parameters with 100% schema description coverage, so the schema already fully documents the parameter situation. The description appropriately doesn't waste space discussing non-existent parameters, maintaining focus on the tool's purpose. This meets the baseline expectation for parameterless tools.

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 action ('List') and resource ('Arc browser spaces'), making the purpose immediately understandable. It doesn't differentiate from siblings like 'list_tabs' or 'focus_space', but it's specific enough to avoid confusion with creation/deletion tools.

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 provides no guidance on when to use this tool versus alternatives like 'list_tabs' or 'focus_space'. It doesn't mention prerequisites, timing considerations, or any contextual factors that would help an agent choose between similar listing operations.

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