MailFixture

get_sms

Full detail of one SMS: text, sender, extracted OTP candidates and classified links, expiry.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "sms_id": "<sms_id>"
    },
    "name": "get_sms"
  }
}

Input Schema

Name	Required	Description	Default
`sms_id`	Yes	SMS id (uuid) from list_sms or wait_for_sms.

Schema Changelog

Changes observed during successful MCP inspections.

First observedJul 11, 2026

TDQS

A4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. It discloses the specific data returned (text, sender, OTP, links, expiry). However, it does not state that the operation is read-only or any side effects, but the nature of 'get' implies no mutation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence with no superfluous words. Essential information is front-loaded and efficiently packed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the single parameter and no output schema, the description adequately covers what the tool returns. It does not mention related sibling tools explicitly, but the context is sufficient for an agent to infer usage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with a clear parameter description ('SMS id (uuid) from list_sms or wait_for_sms'). The tool description adds no extra meaning for the parameter, so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('get') and resource ('SMS'), and details the output fields (text, sender, OTP candidates, links, expiry), clearly distinguishing it from siblings like list_sms (lists) or wait_for_sms (waits for arrival).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied ('Full detail of one SMS'), but no explicit guidance on when to use versus alternatives like get_otp (only OTP) or get_message (possibly email). No when-not-to-use or prerequisites mentioned.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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