list_gmail_labels

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations are absent, so the description carries the full behavioral burden. The verb 'Lists' signals a read-only operation and the Returns section discloses that output is a formatted list with IDs, names, and types, but no context is given on auth prerequisites, inclusion of system labels, pagination, or error behavior.

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 compact: one lead sentence followed by standard Args/Returns sections. Every element is functional, though the docstring format is conventional rather than crafted, and the Returns section partly duplicates the existing output schema.

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 one-parameter read-only listing tool with an output schema, the essentials — action, parameter meaning, and return shape — are present. The gaps are usage routing and behavioral context, but the tool's simplicity keeps the cost of those gaps low.

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%, so the Args section must compensate, and it does: 'user_google_email (str): The user's Google email address. Required.' This documents meaning and requiredness, though it largely restates what the parameter name already conveys and duplicates the schema's required array.

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 opens with a specific verb and resource: 'Lists all labels in the user's Gmail account.' This distinguishes it from sibling tools like manage_gmail_label (mutating label operations) and list_gmail_filters (filters, not labels), so an agent can tell them apart without opening schemas.

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?

No when-to-use guidance appears anywhere in the description. It does not mention alternatives, prerequisites, or cases where a sibling tool like manage_gmail_label or list_gmail_filters would be more appropriate.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.