gmail_list_labelsLists all Gmail system and user labels with their IDs so you can identify and reference the correct label for organizing, filtering, or automating messages.
List Gmail labels (system and user labels) with their ids.
| Name | Required | Description | Default |
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No arguments | |||
| Name | Required | Description | Default |
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No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds only modestly beyond that — the fact that both system and user labels are returned and that IDs are included — without covering volume, pagination, or ordering.
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 front-loaded sentence with zero filler; every clause (system vs user labels, IDs) carries information.
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 read tool with an output schema, the description covers what the tool returns at a high level, so return-value detail is rightly left to the schema. It stops short of noting anything about result size or ordering, a minor gap.
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?
With zero parameters there is nothing to disambiguate, which is the baseline-4 case. The description's note that results carry IDs is the only parameter-adjacent information an agent needs, since no inputs exist.
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 and resource ('List Gmail labels') plus scope ('system and user labels') and what is returned ('their ids'). No sibling tool competes for label retrieval, so explicit differentiation isn't needed, though it isn't provided either.
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 only implied: an agent infers this is the way to discover label IDs before searching or labeling messages. There is no explicit when-to-use clause, prerequisites, or mention of alternatives (of which there are none in the sibling set).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.