payway_get_transactions_by_merchant_ref

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. It discloses the 'last 50' limit and the rate limit of 10 req/min, and the verb 'Retrieve' signals a read-only operation. It omits auth requirements and error behavior, but for a simple lookup the disclosed limits are valuable.

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?

Two short sentences carry the full intent: the first defines the action and scope, and the second adds the only other constraint (rate limit). There is no filler or repetition of schema details.

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 one-parameter lookup tool with no output schema, the description covers the purpose, parameter semantics, result cap, and rate limit. The main missing piece is explicit guidance on when to choose this over related transaction endpoints, but that is more of a usage nuance than a fundamental context gap.

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 schema only defines merchant_ref as a string with maxLength 20, and schema description coverage is 0%. The description compensates by explaining that merchant_ref corresponds to tag 62.01 on KHQR, giving the parameter real-world meaning and clarifying that the tool filters by it. This is meaningful semantic context for the single parameter.

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 states a specific action (Retrieve), a precise resource (transactions), and a distinct filter (merchant_ref / KHQR tag 62.01). It also caps the result set at 50, making the tool's scope unmistakable and differentiating it from more general list or detail tools among the siblings.

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 the use case: call this tool when you have a merchant_ref and need matching transactions. However, it does not explicitly say when not to use it or mention alternatives like payway_get_transaction_list or payway_get_transaction_details, so the agent must infer the best choice from sibling names.

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