star_email

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

With no annotations provided, the description carries the full burden. It discloses that the tool requires an email ID and returns a confirmation object with {id, starred: true}, which is helpful. However, it doesn't mention potential side effects (e.g., whether starring affects email organization or sync), authentication needs, or error conditions, leaving gaps in behavioral context.

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 front-loaded with the core purpose, followed by prerequisites and return value, all in two efficient sentences. Every sentence earns its place by adding necessary information without redundancy or fluff.

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 tool's moderate complexity (a simple mutation with 2 parameters), no annotations, and no output schema, the description does well by covering purpose, prerequisites, and return format. However, it could improve by addressing error cases or confirming idempotency (e.g., what happens if the email is already starred).

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 description coverage is 100%, so the schema already documents both parameters well. The description adds value by specifying that the 'id' should come from specific sibling tools ('list_emails_*' or 'fetch_email_content'), providing practical sourcing guidance beyond the schema's technical definition.

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 action ('Add a star (flag)') and the resource ('to an email'), distinguishing it from sibling tools like 'unstar_email' (which removes stars) and 'list_starred_emails' (which lists starred emails). It specifies the exact operation without ambiguity.

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 clear context by mentioning that the email ID should come from 'list_emails_*' or 'fetch_email_content', guiding the agent on how to obtain the required parameter. However, it doesn't explicitly state when NOT to use this tool or compare it with alternatives like 'unstar_email' for toggling star status.

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