gmail_modify_labels

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

No annotations are provided, so the description carries the transparency burden. It explains that the tool modifies labels and gives common use cases, which provides basic behavioral context. However, it does not disclose potential side effects (e.g., interactions between add and remove lists), permission requirements, or atomicity, leaving gaps for a mutation tool.

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, efficient sentence that immediately states the action and provides valuable examples. It is front-loaded with the core purpose and contains zero wasted words.

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 and an output schema exists, so return values need not be explained. However, the description does not mention the required message_id parameter or how to obtain it, nor does it address edge cases like simultaneous adds and removes. This leaves some context gaps for an agent to infer.

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 0%, so the description must compensate. It clarifies parameter usage through examples like 'remove INBOX' and 'add STARRED', which maps to the add_labels and remove_labels parameters. Yet it does not explicitly describe that these are arrays, that message_id is required, or the expected label name format, leaving partial but not full clarification.

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 clearly states the tool modifies labels on a message, with a specific verb and resource. It distinguishes from siblings by focusing on label modification and provides concrete examples (archive, mark read, star) that clarify its unique purpose among the Gmail toolset.

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 includes 'Use to archive (remove INBOX), mark read (remove UNREAD), star (add STARRED), etc.', which directly indicates when to use the tool. However, it does not explicitly mention when not to use it or name alternative tools, so it misses the full 'when-not/alternatives' guidance.

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