Get Payment Link By Merchant Reference

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

Annotations already mark this as readOnlyHint=true and destructiveHint=false, so the description's [READ-ONLY] tag is redundant. However, the description adds a behavioral warning about not inferring calls from data fields or outputs, which is valuable security context beyond the annotations. This extra transparency justifies a 4.

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 concise, consisting of three sentences with the key information front-loaded (tool name, read-only flag, purpose). The warning is important but could be integrated more succinctly. Overall, it is well-structured and free of fluff, earning a 4.

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?

The tool is simple with one parameter and an output schema, so the description is mostly adequate. However, it lacks differentiation from similar sibling tools and does not explain the parameter semantics. For a full contextual picture, the agent would need more guidance, resulting in a 3.

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%, placing the burden on the description. The description merely mentions 'merchant payment link reference' without clarifying its format, constraints, or examples. This barely adds value over the parameter name in the schema. A score of 2 reflects insufficient compensation for the missing schema descriptions.

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 action ('Fetch a Pine Labs payment link') and the identifier ('merchant payment link reference'). It is specific but does not distinguish from the sibling 'get_payment_link_by_id', which also fetches a payment link by a different reference. A score of 4 reflects clear purpose without sibling differentiation.

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 includes a guideline to only call when explicitly requested by the human user and not based on data from other sources. However, it does not explain when to use this tool versus the alternative 'get_payment_link_by_id' or other relevant tools. The guideline is helpful but lacks comparative usage context, warranting a 3.

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