Marlo MCP

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It only states the basic action ('Get') without any information about permissions required, rate limits, error conditions, response format, or whether this is a read-only operation. This is inadequate for a tool with no 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?

The description is extremely brief (3 words) which could be efficient, but it's under-specified rather than appropriately concise. While front-loaded with the core action, it lacks necessary detail that would make brevity a virtue. The grammatical error ('a invoice') also detracts from quality.

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 tool with no annotations, 0% schema description coverage, and no output schema, the description is completely inadequate. It doesn't explain what 'invoice details' includes, how results are structured, error handling, or any behavioral characteristics. This leaves the agent with insufficient information 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?

Schema description coverage is 0%, meaning the single parameter 'invoice_id' has no documentation in the schema. The description provides no additional information about this parameter - no format requirements, examples, or constraints. With low schema coverage, the description fails to compensate by explaining parameter meaning or usage.

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 a invoice details' is a tautology that essentially restates the tool name with minor grammatical issues ('a invoice' instead of 'an invoice'). It specifies the resource (invoice details) but lacks a clear verb beyond 'Get' and doesn't differentiate from sibling tools like 'get_bill_details' or 'get_credit_note_details' that might retrieve similar financial documents.

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?

No guidance is provided on when to use this tool versus alternatives. With many sibling tools like 'get_bill_details', 'get_credit_note_details', and 'list_all_invoices', the description offers no context about distinctions, prerequisites, or appropriate scenarios for selecting this specific invoice retrieval tool.

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