Fetch full details for one PikaSim eSIM plan by the id returned from search: coverage, data, voice/SMS allowance, duration, price, networks, and its pikasim.com purchase URL. Read-only.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The plan id returned by the search tool (the packageCode) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnlyHint annotation, the description lists the exact data points returned (coverage, data, voice/SMS allowance, duration, price, networks, URL), which is valuable since there is no output schema. The redundant 'Read-only' statement adds little, but the field enumeration gives transparency into the tool's 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 first sentence is dense and informative, front-loading the core purpose and return fields. The second sentence 'Read-only.' is redundant with the annotation, making it slightly wasteful, but overall the description is compact.
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 one-parameter read-only tool, the description adequately covers return values and usage context, especially since there is no output schema. It does not mention error behavior (e.g., invalid id), but that is a minor gap for a fetch-by-id operation.
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?
The schema already provides a clear description for the id parameter as 'The plan id returned by the search tool (the packageCode)'. The description's phrase 'by the id returned from search' adds no new information, so the semantic value is baseline.
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 fetches full details for one PikaSim eSIM plan using the id from search, and enumerates the specific fields returned. However, it does not explicitly distinguish itself from the sibling tool get_package_details, which may serve a similar purpose.
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 context: use this after search to get comprehensive plan details by the returned id. It does not explicitly state when not to use it or mention alternative tools, but the use case is well implied.
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.