update-email

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

Annotations declare idempotentHint=true, and description explicitly states 'idempotent — safe to retry', adding context. It details the effect of each action (toggles isRead, sets/clears flag, marks complete). No contradiction with annotations.

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?

Description is a single paragraph of about 5 sentences, informative but could be more structured with bullet points or shorter sentences. However, no unnecessary information is present.

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 no output schema, the description mentions 'Returns status confirmation per message', which is sufficient. It covers all actions and parameters completely.

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 significant meaning beyond the input schema: it explains which actions use which parameters (e.g., dueDateTime only for flag, ids for batch flag/unflag/complete) and clarifies that id is required for mark-read/mark-unread. Schema coverage is 100% but description still adds value.

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?

Description clearly states it updates message state without modifying content. The verb 'Update' along with specific actions (mark-read, unflag, etc.) precisely indicates what the tool does. It distinguishes from sibling tools like 'read-email' or 'send-email'.

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?

Description provides specific guidance on when to use each action and which parameters are required (e.g., id for mark-read/mark-unread, ids for batch flag operations). It mentions batch efficiency but lacks explicit when-not-to-use or references to alternative tools.

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