list_email_sendersList configured "From" senders and the active provider.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| data | No | The configured senders — each with its id, from_name, from_email, reply_to and whether it is the default — alongside the account's active email provider. | |
| success | Yes | True when the call succeeded. A failure comes back as an error result instead. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, establishing a safe read operation. The description adds valuable context by specifying that the tool returns both the configured 'From' senders and the active provider, going beyond the tool name. No side effects or special behaviors are relevant, so the description is adequate.
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 description is a single, front-loaded sentence with no filler. Every word contributes meaning, and it avoids unnecessary detail. It is appropriately concise for a simple, read-only list tool.
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 zero-parameter tool with an output schema, the description is sufficient. It explains the core function and the two key outputs. An agent can invoke it without further clarification. The only minor gap is that it doesn't specify whether the list is empty or what constitutes an 'active' provider, but the output schema should cover the response structure.
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 tool has zero parameters, and the schema coverage is trivially 100%. The description does not need to explain parameters. It adds semantic value by indicating the content of the response (senders and provider), which is beyond the empty schema. The baseline of 4 for zero parameters is appropriate.
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 action ('List'), the resource ('configured From senders'), and the additional output ('active provider'). It is specific enough to distinguish from sibling list tools like list_email_templates or list_email_logs, and leaves no doubt about what the tool returns.
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?
No guidance is given about when to use this tool versus alternatives. While the purpose is unambiguous, there is no mention of related tools like get_email_provider or set_default_email_sender that might be relevant in different contexts. The description does not explicitly state when to prefer this tool.
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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