get_esim_qrFetch an eSIM activation QR code as an image so users can scan it directly from MCP clients that render images inline.
Fetch the activation QR code for an eSIM as an image. Most MCP clients render the image inline so the user can scan it directly.
| Name | Required | Description | Default |
|---|---|---|---|
| esim_id | Yes | esim_... id |
| Name | Required | Description | Default |
|---|---|---|---|
| esim_id | Yes |
Changes observed during successful MCP inspections.
v1.2.1Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": {},
+ "properties": {
+ "esim_id": {
+ "type": "string"
+ }
+ },
+ "required": [
+ "esim_id"
+ ],
+ "type": "object"
+}v1.1.8Input schema / properties / esim_id / descriptionAdded value: +"esim_... id"Input schema / properties / esim_id / patternAdded value: +"^(?:esim_[A-Za-z0-9_-]{1,64})$"v1.1.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the payload is an image and most clients render it inline, which matters for how the agent presents the result.
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 short sentences, zero waste, and the core action is front-loaded before the rendering note. Every sentence earns its place.
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?
With annotations covering safety and an output schema covering return values, the description only needs to explain the action and the image behavior, which it does. It could note failure modes (invalid or unprovisioned esim_id), but nothing essential 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?
One parameter with 100% schema description coverage and a pattern constraint, so the schema carries the semantics. The description adds nothing about the esim_id beyond what the schema documents, making the baseline 3 correct.
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 (Fetch), resource (activation QR code for an eSIM) and the return modality (as an image). An agent can distinguish it from sibling read tools like get_esim_status or get_esim_qr-style lists without opening the schema.
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?
Usage is implied rather than stated: it explains that the image renders inline for the user to scan, which implies when this tool is useful, but it never names an alternative or a when-not condition (e.g. if the user only wants status, use get_esim_status).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.