get-received-email-attachmentRetrieve any attachment from a received email using its email ID and attachment ID, and receive a time-limited download URL to access the file directly.
Retrieve details of a specific attachment from a received email, including a time-limited download URL.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The attachment ID | |
| emailId | Yes | The received email ID |
Changes observed during successful MCP inspections.
v2.12.0Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v2.10.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnlyHint annotation, the description adds the behavioral detail that the download URL is time-limited, which is valuable context for agents. This goes beyond the basic safe-read indication and informs expectations about URL expiry.
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, well-structured sentence that front-loads the primary purpose and includes a key detail about the output. Every word adds value, with no redundancy or clutter.
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 two-parameter retrieval operation with readOnlyHint and no output schema, the description sufficiently covers what it does and the nature of the response (details + time-limited URL). It is complete enough for an agent to select and invoke correctly.
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?
Schema description coverage is 100% for both parameters, and they are clearly named. The description adds minimal parameter-specific meaning beyond mapping emailId to 'received email' and id to 'attachment', so it does not significantly elevate the baseline.
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 specific verb ('Retrieve details') and clearly identifies the resource ('a specific attachment from a received email'), including a notable output trait ('time-limited download URL'). This distinguishes it from siblings like get-sent-email-attachment.
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 phrase 'from a received email' provides clear context for when to use this tool, implicitly differentiating it from sent-email attachment tools. No explicit exclusions or alternatives are named, but the usage context is unambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.