Returns the prepaid spending balance of the connected PikaSim agent wallet, in USD. Read-only; makes no changes. Call this before purchase_esim or purchase_phone_plan to confirm sufficient funds, or any time you need the current balance. Requires a connected agent wallet (OAuth or ak_live_ key). If no wallet is connected, the result explains how to connect one.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnlyHint annotation, the description adds that it 'makes no changes', requires a connected agent wallet (OAuth or ak_live_ key), and explains that if no wallet is connected, the response guides the user on connecting one. This discloses auth requirements and error behavior.
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: three sentences with the primary purpose front-loaded, followed by usage guidance, prerequisite, and error behavior. No redundant or irrelevant content.
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 zero-parameter, read-only balance check with no output schema, the description covers the return value, prerequisites, when to use, and error handling. It is fully sufficient for an agent to invoke and interpret results.
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?
This tool has zero parameters, so the description need not explain parameter details. The baseline of 4 applies, and no additional parameter context is necessary or provided.
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 specifically states the tool 'Returns the prepaid spending balance of the connected PikaSim agent wallet, in USD', using a clear verb and resource. It differentiates from sibling tools by focusing on balance retrieval and explicitly naming related purchase tools.
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?
Provides explicit usage guidance: 'Call this before purchase_esim or purchase_phone_plan to confirm sufficient funds, or any time you need the current balance.' Also notes a prerequisite (connected wallet) and what happens if unmet.
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.
There is notable overlap between search tools (search, search_esim_packages, search_phone_plans) and detail tools (fetch, get_package_details, get_pricing, get_phone_plan_pricing). While descriptions clarify some differences, agents may struggle to pick the right tool without careful reading, especially between 'search' and 'search_esim_packages' and between 'fetch' and 'get_package_details'.
Most tools follow a clear verb_noun convention (e.g., purchase_esim, list_orders, get_balance). A few are single verbs like 'fetch' and 'search', which stand out but are still recognizable as actions. Overall the pattern is predictable and readable.
With 31 tools, this is a large set. The server covers several distinct sub-domains (eSIM data, phone-number eSIM, SMS verification, SMS rentals, wallet management), which justifies some size, but the count is on the high side and could be consolidated (e.g., merging search tools or detail-fetching tools).
The tool surface covers the full lifecycle for each product line: search, view details, purchase, list, check status, top-up/cancel, plus wallet management. The only minor gap is a lack of explicit update tools (e.g., changing a phone plan), but core workflows are well supported.