Marlo 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 but offers nothing beyond the basic operation name. It doesn't indicate whether this is a read-only operation, whether it requires authentication, what the response format might be, whether it supports pagination (though the schema suggests it does), or any rate limits. This leaves the agent completely in the dark about behavioral characteristics.

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 technically concise with just three words, this represents under-specification rather than effective brevity. The description fails to provide any meaningful information that would help an agent understand or use the tool. Every word earns its place only in the most literal sense, but the description as a whole fails to serve its purpose.

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 (13 properties in the query object), absence of annotations, and lack of output schema, the description is completely inadequate. It provides no information about what the tool returns, how to filter results, authentication requirements, or error conditions. For a data retrieval tool with rich filtering capabilities, this minimal description leaves the agent unable to use the tool effectively.

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 description provides zero information about parameters, while the schema has 0% description coverage (though it does have parameter definitions with descriptions). The description doesn't mention any filtering, sorting, or pagination capabilities that the schema reveals. For a tool with 1 required parameter (a complex object with 13 properties), this represents a critical gap in understanding how to use the tool effectively.

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 'list all bills' is essentially a tautology that restates the tool name without adding meaningful context. While it indicates a listing operation on bills, it doesn't specify scope, format, or any distinguishing characteristics from sibling tools like 'get_bill_details' or other list_* tools. It provides the minimum verb+resource pairing but lacks specificity.

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 absolutely no guidance on when to use this tool versus alternatives. With sibling tools like 'get_bill_details' and 'list_all_invoices' present, there's no indication of whether this tool should be used for summaries versus details, filtering capabilities, or any prerequisites. The agent receives zero contextual usage information.

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