Get the USD price and voice/SMS/data allowance for a specific PHONE-NUMBER eSIM. Accepts the packageCode from search_phone_plans.
| Name | Required | Description | Default |
|---|---|---|---|
| currency | No | Currency code (currently only USD supported) | |
| packageCode | Yes | Phone-plan package code from search_phone_plans (e.g., change-plus-7days-1gb) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint=true and openWorldHint=true, so the description's job is to add context. It adds the return values (USD price and voice/SMS/data allowance) and clarifies the input source, which is useful. No contradictions with annotations.
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 the main purpose, and no wasted words. Every sentence contributes meaning.
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?
Given the low complexity (2 params, no output schema), the description covers the essential aspects: what the tool returns, what input it needs, and where that input comes from. It could mention edge cases or error conditions, but for this simple read operation, it is sufficiently 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 description coverage is 100%, so the schema already explains both parameters. The description adds minimal extra meaning (pointing to search_phone_plans as source), but the schema already provides examples and the currency limitation. This meets the baseline but does not exceed it.
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 a specific action ('Get the USD price and voice/SMS/data allowance') for a specific resource ('PHONE-NUMBER eSIM'), and distinguishes from siblings by referencing the source packageCode from search_phone_plans. This is a specific verb+resource+scope, making it easy to differentiate from other pricing 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?
The description provides clear usage context: it is used after search_phone_plans to retrieve pricing for a specific packageCode. It does not explicitly list exclusions or alternative tools, but the flow is implied and sufficient for correct selection.
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.