martin_arcade

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

With no annotations provided, the description carries the full burden, and it does so well. 'Presentation-only' and 'cannot change governed execution or evidence' accurately disclose both what the tool does and what it will not do, giving the agent clear safety expectations.

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 two compact sentences with no filler. The first sentence front-loads the action and preconditions, and the second adds the essential limitation. Every sentence earns its place.

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 zero-parameter tool with no output schema, the description provides everything needed: what happens, when it should happen, and what side effects it cannot have. No important invocation information is missing.

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 and the schema is already fully covered. With no parameters to document, the description does not need to add parameter explanations; the baseline for zero-parameter tools applies.

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 specific action ('Open') and a distinct resource ('MartinLoop Arcade') and scopes it as presentation-only. It differentiates the tool from the run/eval/status siblings by emphasizing it is strictly a display surface, not a control surface.

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 explicitly states the condition under which the tool should be used ('when the host supports MCP Apps'). It also tells the agent not to use it for mutating or governed workflows by clarifying that the Arcade 'cannot change governed execution or evidence'.

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