Star / Unstar Email

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

The description contradicts the annotation 'idempotentHint: true' by stating it toggles the star status, which is inherently non-idempotent. Additionally, it does not disclose that the operation may silently fail if sourceFolder is omitted incorrectly.

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 two well-structured sentences with no filler. The first sentence defines the purpose, and the second provides a key usage tip, earning top marks for efficiency.

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 description covers the basic purpose and a critical parameter tip, but it omits details about the return value (despite an output schema) and fails to mention that the tool operates on a single email, which is important given the sibling 'bulk_star'. The lack of an explicit note about the required 'emailId' is a gap.

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?

The description adds the default value for 'isStarred' and a brief condition for 'sourceFolder', but the schema already provides a detailed description for 'sourceFolder'. The other two parameters lack any additional meaning beyond the schema.

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 it toggles the starred status of an email, with a specific verb and resource. However, it does not explicitly distinguish this tool from siblings like 'bulk_star', so it misses the highest mark.

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 provides a usage tip for the 'sourceFolder' parameter but offers no guidance on when to use this tool versus alternatives (e.g., bulk_star). There is no explicit when-to-use or when-not-to-use context.

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