Batch Modify Gmail Message Labels

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

The description adds the behavioral detail that the operation is performed as a single batch request, which is useful beyond the annotations. Annotations already flag destructive and non-read-only behavior; the description does not contradict them and provides mild additional context about the batch nature.

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 a single sentence that is front-loaded with the action and resource, and contains no filler or redundant information. Every word 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?

Given the presence of a full output schema, detailed annotations, and 100% parameter schema coverage, the description is concise but complete for a batch label modification tool. No critical behavioral or usage context is missing.

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%, so all four parameters have descriptions in the schema. The tool description does not add any parameter-specific meaning beyond what is already stated, which meets the baseline but does not exceed it.

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 states a specific verb ('Adds or removes'), a clear resource ('labels from multiple Gmail messages'), and a distinguishing scope ('in a single batch request'). This clearly differentiates it from the sibling tool modify_gmail_message_labels, which handles single messages.

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?

The phrase 'in a single batch request' gives clear usage context: use this when modifying multiple messages at once. It does not explicitly name the alternative single-message tool or state exclusions, but the context is clear enough for an agent to infer when it applies.

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