get_payment_hub

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

With no annotations, the description carries the full burden. It discloses what the tool returns (health metrics, supported currencies/countries, limits) and explicitly mentions the NOT_FOUND error for invalid IDs, which is useful behavioral context. It does not mention auth or rate limits, but for a simple read-only getter, this is adequate.

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. The first sentence front-loads the purpose and return data; the second covers error behavior. Every word earns its place with no fluff or repetition.

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 simple getter with one parameter and no output schema, the description sufficiently covers input, output, and error cases. It lists all key return fields and the error condition, making it self-contained and complete for its complexity.

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 coverage is 100% with a clear description and examples for the 'id' parameter. The tool description adds no extra semantic value beyond what the schema already provides; mentioning 'hub ID' in the error case is redundant. Baseline 3 is appropriate.

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 uses a specific verb ('Get'), identifies the resource ('a payment hub'), and clearly states the scope ('current details and health metrics'). It lists the exact data returned (status, currencies, countries, limits, latency, success rate), distinguishing it from sibling tools that list hubs or transactions.

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 clearly implies when to use this tool (when you need a single hub's details/health), and the error behavior indicates it's for an existing hub. However, it does not explicitly name alternatives like list_payment_hubs or state exclusions, so it falls slightly short of full guideline clarity.

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