mail_list_flagged

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

Beyond the annotations (readOnly, idempotent, non-destructive), the description adds valuable behavioral context: requires Mail.Read permission, returns specific fields (id, subject, sender, date, preview), orders newest first, and explains the meaning of flags as the user's own marker. This enriches the agent's understanding substantially.

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 sentences, front-loaded with the core action, and every clause adds meaningful information. It efficiently covers purpose, scope, ordering, return fields, permissions, and usage distinction without any 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?

For a simple list tool with one optional parameter and no output schema, the description is remarkably complete. It specifies the user scope, ordering, return fields, permission requirement, and the conceptual purpose, leaving little ambiguity about behavior.

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 single parameter max_results is fully documented in the schema with a clear description ('Maximum flagged emails to return'), so schema coverage is 100%. The tool description does not add further detail about the parameter, which is acceptable given the schema already covers it. Baseline 3 is appropriate.

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 lists emails flagged for follow-up, with a specific verb and resource, and explicitly distinguishes it from mail_list_recent by noting the latter returns everything regardless of state. This makes the purpose unambiguous and sibling-differentiated.

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 explicit guidance: use for 'what do I still need to deal with' rather than mail_list_recent, which is an alternative tool. This directly addresses when to use this tool and gives an exclusion, meeting the highest bar for usage guidelines.

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