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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond the annotations: it is a GET lookup, it returns status/amount/destination/discount, and it is keyed by the original send response id. It does not discuss error cases, rate limits, or auth requirements, but those are secondary for a simple read endpoint.

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 one compact sentence that front-loads the purpose, identifier origin, returned fields, and HTTP method. Every clause adds value with no filler.

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 single-parameter read tool, the description is complete: it identifies the lookup key, its source, and the key result fields. With annotations covering safety and a 100%-covered schema, no critical agent-facing information is missing.

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%, and the single parameter is already documented with an ATPid_ example. The description adds useful semantic origin by noting this is the requestId/ATPid_ from a send reply, which helps an agent know where to get the value. That goes slightly beyond the schema, though the schema already carries most of the burden.

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?

States a specific verb and resource: look up an airtime transaction by transaction id. It names the exact identifier format (requestId / ATPid_...) and enumerates the returned fields, making it easy to distinguish from `africastalking_send_airtime` and `africastalking_find_mobile_data_transaction`.

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 establishes the usage context: the transaction id comes from a send reply, so this tool is for checking a previously submitted airtime transaction. It does not explicitly state when not to use this tool or name the sibling finder for mobile data, but the intended scenario is clear.

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