List Gmail Accounts

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false. Beyond that, the description adds auth constraints ('share tokens cannot call', 'API key required'), a cost signal ($0.05), and a migration caveat for multi-mailbox behavior — real context not present in structured fields.

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?

Front-loaded with the core action, followed by tightly packed usage, connection, auth, and pricing notes in a few short clauses. Dense but each clause carries information; minor parentheses-packed pricing note is the only slight 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 parameterless read tool with a rich output schema, the description covers purpose, downstream usage, auth limits, connection path, and cost. The only gap is that the '/integrations (multi-mailbox after migration)' clause is terse and slightly ambiguous.

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?

Zero input parameters, so the baseline is 4. The description instead documents the shape of the result (id, email, is_default), which is meaningful even though an output schema already exists.

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 connected Gmail mailboxes for the authenticated user') and even enumerates the returned fields (id, email, is_default). An agent can distinguish it from search_gmail or read_gmail_message without opening any schema.

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?

Explicitly routes the agent: use the returned account identifier on search_gmail / read_gmail_* / import_*_gmail, and points to /integrations for connecting another inbox. It gives clear context for calling this first, though it never states an explicit 'when not to use' case.

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