Marlo MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. However, it offers no information beyond the basic action of 'getting' data. It doesn't specify whether this is a read-only operation, if it requires authentication, what the return format might be, or any potential side effects like rate limits. This is inadequate for a tool with zero annotation coverage.

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?

While the description is extremely concise ('get interest rates'), this brevity stems from under-specification rather than efficient communication. It lacks necessary details and structure, failing to provide a clear, front-loaded explanation of the tool's purpose or behavior. Conciseness should not come at the cost of clarity, making this score low.

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 complexity of financial data tools and the lack of annotations or output schema, the description is insufficient. It doesn't explain what 'interest rates' entail, the scope of data returned, or how results are structured. With no output schema to clarify return values, the description should provide more context to be complete, but it does not.

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 0 parameters, and the schema description coverage is 100% (since there are no parameters to describe). In such cases, the baseline score is 4, as there are no parameters for the description to compensate for or add meaning to. The description doesn't need to explain parameters, so this dimension is inherently well-covered.

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 'get interest rates' is a tautology that merely restates the tool name without adding any meaningful clarification. It doesn't specify what type of interest rates (e.g., current market rates, historical rates, specific to loans or investments), nor does it distinguish this tool from potential sibling tools that might also retrieve financial data. While it indicates a retrieval action, the purpose remains vague and under-specified.

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. It doesn't mention any context, prerequisites, or exclusions, and given the many sibling tools (e.g., get_market_rates, get_market_rate_details), there's no indication of how this tool differs or when it should be selected. This leaves the agent without any usage direction.

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