star_email

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

Discloses use of IMAP Flagged flag and toggling based on isStarred. No annotations exist, so description carries burden; lacks mention of permissions or syncing, but acceptable.

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 concise sentences, no fluff. Front-loaded with action and method, then usage guidance.

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?

Sufficient for a simple toggle tool. No output schema, but description covers purpose, method, and alternatives adequately.

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?

Description clarifies isStarred parameter via 'star or unstar', adding meaning beyond schema's default. Schema covers emailId format; description reinforces usage.

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?

Clearly states it stars/unstars a single email using IMAP Flagged flag. Distinguishes from sibling batch_email_action by noting single use case.

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 recommends batch_email_action for multiple emails, guiding when not to use this tool. Provides clear context for single-email use.

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