Read a complete Gmail thread conversation using account and thread IDs, solving the limitation that SMTP cannot fetch thread histories.
Read a Gmail thread. SMTP cannot read threads.
| Name | Required | Description | Default |
|---|---|---|---|
| thread_id | Yes | ||
| account_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description aligns with the readOnlyHint annotation and adds useful context about Gmail threads and SMTP limitations. However, it does not disclose additional behaviors such as output format, authentication requirements, or error cases beyond what annotations already indicate.
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 extremely concise: two short sentences, with the core purpose front-loaded and the rationale placed second. Every word earns its place.
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?
The tool is simple, has an output schema, and a readOnly annotation, so much of the necessary information is already structured. However, the sibling relation with mail_read is ambiguous, and the lack of parameter semantics leaves some gaps in practical usability.
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 0%, and the description does not explain the parameters account_id or thread_id. The names are somewhat self-explanatory, but the description adds no meaning beyond the input schema, so it fails to compensate for the low coverage.
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 tool's function with a specific verb and resource: 'Read a Gmail thread.' It does not explicitly differentiate from the sibling mail_read tool, though the mention of SMTP hints at the protocol context.
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 'SMTP cannot read threads' provides an implicit rationale for using this tool instead of SMTP-based alternatives, but it does not explicitly state when to choose mail_thread over mail_read or other sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.