Modify Gmail Message Labels

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

Annotations already indicate destructive hints (destructiveHint: true). The description adds behavioral context by explaining how to archive (remove INBOX) and delete (add TRASH). This goes beyond annotations without contradicting them. It could disclose more about authorization requirements or error handling, but what is provided is helpful.

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 extremely concise: two sentences plus two bullet-point examples. It front-loads the core action and adds no extraneous information. Every sentence 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?

The tool is simple (modify labels on a single message) and the description, combined with schema annotations and presence of an output schema, covers the essentials. It could mention what happens with invalid label IDs, but for typical use, it is sufficiently complete.

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 100% coverage with descriptions for each parameter. The description adds value by providing concrete examples (archive, delete) that illustrate how to use add_label_ids and remove_label_ids effectively. This goes beyond the schema's parameter descriptions.

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 starts with 'Adds or removes labels from a Gmail message,' clearly stating the verb and resource. It provides specific examples (archive and delete) that distinguish it from sibling tools like 'manage_gmail_label' or 'batch_modify_gmail_message_labels'.

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 description gives explicit context for use (adding/removing labels) and even suggests common tasks (archive by removing INBOX, delete by adding TRASH). However, it does not mention when not to use this tool versus alternatives like 'manage_gmail_label' for label management or 'batch_modify_gmail_message_labels' for multiple messages.

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