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. |
Changes observed during successful MCP inspections.
Input schema / $schemaRemoved value: -"http://json-schema.org/draft-07/schema#"Output schema / $schemaRemoved value: -"http://json-schema.org/draft-07/schema#"Output schema / properties / success / descriptionPrevious value: -"True when the call succeeded. A failure comes back as an error result instead."New value: +"True when the call succeeded."Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is safe. The description adds the 'active provider' detail, which is useful behavioral context beyond the title. However, it does not disclose the return shape or any ordering/filtering behavior, though for a simple list tool this is acceptable.
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?
A single, compact sentence that states the operation and its scope. Every word is functional, with 'configured' and 'active provider' adding real meaning rather than padding.
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 no parameters, an output schema present, and annotations covering the safety profile, the description is complete enough for an agent to call this tool correctly. There is no missing prerequisite, authentication note, or complex behavior that needs explanation.
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, so parameter semantics are trivial. The baseline for a 0-parameter tool is 4, and the description does not need to explain anything further. It correctly avoids inventing parameter-like detail.
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 uses a precise verb+resource combination: 'List configured "From" senders and the active provider.' It is not a tautology of the title, and it adds the useful qualifier 'configured' and the extra 'active provider' element. This clearly separates it from sibling tools like list_email_templates.
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 clearly conveys what context this tool fits: retrieving the configured sender identities and provider state. It does not explicitly name alternatives or exclusions, but with zero parameters and a read-only purpose, the usage context is self-evident and no conflicting alternative exists among the sibling list tools.
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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