xendit-mcp

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

No annotations are provided, so the description carries full burden. It mentions the return type ('Returns array of matching disbursements'), which is helpful, but lacks details on error handling, rate limits, authentication requirements, or what happens if no matches are found. For a lookup tool with zero annotation coverage, this leaves significant behavioral gaps.

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 concise sentences with zero waste. The first sentence states the purpose and key parameter, while the second specifies the return value. It's front-loaded and efficiently communicates essential information without redundancy.

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 no annotations, no output schema, and a simple single-parameter input schema, the description covers basic purpose and return type but lacks details on error cases, pagination, or example usage. It's minimally adequate for a lookup tool but could be more complete to guide the agent 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 100%, with the parameter 'externalId' well-documented in the schema. The description adds minimal value by noting it's 'usually CareNow reference', providing slight contextual meaning beyond the schema's 'external_id used when creating the disbursement'. Baseline 3 is appropriate as the schema does most of the work.

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: 'Look up disbursements by your external_id' specifies the verb (look up) and resource (disbursements). It distinguishes from sibling 'xendit_get_disbursement' by focusing on external_id lookup rather than general retrieval, though the distinction could be more explicit.

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 implies usage context by mentioning 'external_id (usually CareNow reference)', suggesting it's for retrieving disbursements created with a specific external identifier. However, it doesn't explicitly state when to use this versus alternatives like 'xendit_get_disbursement' or other sibling tools, leaving some ambiguity.

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