check_data_balanceCheck remaining data balance on an eSIM. Requires a session key and the eSIM's ICCID.
| Name | Required | Description | Default |
|---|---|---|---|
| iccid | Yes | The ICCID of the eSIM to check | |
| session_key | Yes | Session key from a previous tool call |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description aligns with the readOnlyHint annotation, indicating a read operation. No contradictions, but it adds little behavioral context beyond what annotations already convey (e.g., no mention of rate limits or session key validity).
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 sentences, front-loaded with purpose, followed by requirements. No unnecessary words.
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 read tool with no output schema, the description is functional but lacks hints about return values (e.g., balance unit or format). Acceptable but not complete.
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%, and the description merely restates the required parameters without adding new meaning or format hints. Baseline of 3 applies since the schema already documents parameters.
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 checks remaining data balance on an eSIM, with a specific verb and resource. It distinguishes from sibling tools like buy_topup or check_order_status.
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 lists required inputs (session key and ICCID) but provides no guidance on when to use this tool versus alternatives or when not to use it. This is adequate but lacks contextual usage advice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool has a clearly distinct purpose: buying top-ups, checking balances, checking order status, creating orders, getting business context, fetching package details, listing eSIMs, searching packages, and searching top-up packages. No overlapping functionality.
All tool names follow a consistent verb_noun pattern in snake_case. Verbs like 'get', 'list', 'search', 'create', 'buy', 'check' are used appropriately, making the naming predictable.
With 9 tools, the server is well-scoped for managing eSIMs. It covers browsing packages, ordering, checking status and balance, listing eSIMs, and handling top-ups without being overwhelming.
The tool set covers the main lifecycle: search, create order, check order status, list eSIMs, check balance, and top-up. Missing features like cancellation or order history are minor gaps, but the core workflows are well-supported.