Amazing Marvin MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes what the tool does (tests connection/credentials) and what it returns (OK or error details). However, it doesn't mention potential side effects, rate limits, or authentication requirements beyond what's implied by 'credentials.'

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 with three sentences that each earn their place: purpose statement, usage guidelines, and return value explanation. No wasted words, and the most critical information appears first.

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 that an output schema exists, the description doesn't need to fully explain return values. For a simple diagnostic tool with one optional parameter, the description provides adequate context about purpose and usage. However, the complete lack of parameter documentation slightly reduces completeness.

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 input schema has 0% description coverage for its single parameter 'debug'. The tool description doesn't mention this parameter at all, providing no additional semantic information beyond what the bare schema provides. With one undocumented parameter, this represents a clear gap.

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 tool's purpose with a specific verb ('Test') and resource ('API connection and credentials'). It distinguishes itself from all sibling tools, which are focused on task/project management operations rather than connection testing.

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 provides usage guidelines: 'Use when troubleshooting connection issues or verifying API setup.' This gives clear context for when to invoke this tool versus the many sibling tools that perform data operations.

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