Rename an existing Gmail label without losing conversations assigned to it; use Parent/Child in the new name to nest the label under an existing one.
Rename a user label (Gmail settings -> Manage labels -> label -> Name). Conversations keep it.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Exact current name of the user label. | |
| new_name | Yes | New name ('Parent/Child' nests it under an existing label, as in Gmail). |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. 'Conversations keep it' is a genuine, useful disclosure that renaming does not strip the label from existing conversations, and 'user label' hints at the system-label restriction. However, nothing is said about name collisions, reversibility, or whether the old name remains searchable.
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?
Two compact clauses with the operation stated first and the persistence note second; nothing is padded. The 'Conversations keep it' fragment is terse to the edge of ambiguity but still 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?
For a simple two-parameter tool whose schema is fully documented, the essentials are covered. But it is a mutation with no annotations and no output schema, and the description leaves the agent without error/collision behavior or any confirmation of what the call returns.
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 coverage is 100% and both parameters are documented, including the 'Parent/Child' nesting behavior. The description adds nothing about parameters beyond what the schema already states, so baseline 3 applies.
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?
States a specific verb ('Rename') and a scoped resource ('a user label'), which cleanly separates it from gmail_create_label, gmail_delete_label, and gmail_label without needing to name them. The 'user label' qualifier also implies the system-label boundary.
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?
Usage is implied by the verb and the Gmail settings path, but there is no explicit when-to-use/when-not statement or named alternative. An agent must infer that create/delete exist elsewhere and that system labels are out of scope.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.