List Gmail accounts saved on this computer

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

Without annotations, description carries full burden. It states tool returns aliases (strings) with no side effects. It doesn't mention authentication or file reading, but for a simple list operation this is sufficient transparency.

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 sentences with no wasted words. Information is front-loaded: first sentence states what it does, second explains how to use the output. Perfectly concise.

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 tool with no output schema, description fully covers purpose and integration with sibling tools. An agent would understand exactly what to expect and how to use the result.

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?

Input schema has zero parameters, so baseline is 4. Description adds value beyond schema by explaining the nature of returned values and their usage in other tools, making it highly informative.

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?

Title and description clearly state tool returns token file aliases for saved Gmail accounts. It explains the output are strings. While it doesn't explicitly differentiate from sibling multi_gmail_accounts, the context is clear.

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?

Description provides specific guidance: pass the alias as accountAlias on other tools when MCP client shares one default session. This gives clear context for when to use the tool, though it does not list alternatives or when not to use.

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