addy-mcp

set_username_default_recipient

Idempotent

Set or clear the default recipient for aliases on a username, and use null to fall back to the account default.

Instructions

Set (or clear) the default recipient for aliases on a username.

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": {
      "username_id": "<username_id>",
      "recipient_id": "<recipient_id>"
    },
    "name": "set_username_default_recipient"
  }
}

Input Schema

Name	Required	Description	Default
`username_id`	Yes	The id (UUID) of the item
`recipient_id`	Yes	Recipient id, or null to use the account default

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.2Nov 12, 2026

TDQS

A3.8/5.0

Behavior3/5

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

The annotations already establish a non-read-only, idempotent, non-destructive operation, and the description adds that the operation affects an alias default and can be cleared. It does not explain whether existing aliases are changed, how explicit alias recipients interact with the default, or what validation or response to expect.

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?

One short, front-loaded sentence states the action, target, scope, and clear case without filler. Its parenthetical is efficient rather than distracting.

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?

For a simple two-parameter mutation with fully described inputs and safety annotations, this is enough for basic selection and invocation. It would be more complete with explicit scope comparisons and a brief statement of the default's effect on aliases, especially since there is no output schema.

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%, including the UUID username_id and nullable recipient_id with null meaning account default, so the baseline is 3. The phrase 'or clear' aligns with that nullable parameter but adds no syntax, validation, or selection semantics beyond the schema.

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

Purpose4/5

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

The description gives a specific action and resource: setting or clearing the default recipient used for aliases attached to a username. That scope is clear, but it does not explicitly distinguish this username-level default from the domain-level sibling or direct alias-recipient setters.

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

Usage Guidelines4/5

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

The wording supplies clear context for using the tool for a username-wide default and includes the clear-default case. It gives no explicit when-not guidance or routing to set_domain_default_recipient or set_alias_recipients when a different scope is needed.

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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