Mark Email Read/Unread

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

Annotations already indicate it's a write operation that is idempotent and non-destructive. Description adds value by disclosing the default for isRead and the critical behavior about IMAP UID folder-scoping and silent no-ops. No mention of rate limits or auth, but annotations cover the core safety profile.

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 succinct sentences with no wasted words. Front-loaded with the core action and immediately followed by key usage hints.

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 boolean toggle, the description covers the essential behavioral nuance (source folder). Annotations confirm safety. Output schema exists. Could mention that it operates on a single email, but that is implicit from the singular emailId parameter.

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 descriptions exist for account_id and sourceFolder, but isRead and emailId lack schema descriptions. Description adds the default for isRead and reiterates the importance of sourceFolder. With 50% schema coverage, the description partially compensates but could provide more detail on emailId format.

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 sets the read/unread status of an email, which is a specific verb and resource. It differentiates from siblings like bulk_mark_read (for bulk) and star_email (for starring).

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 explicitly advises when to pass sourceFolder to avoid silent no-ops, but does not provide guidance on when to use this tool versus alternatives like bulk_mark_read or star_email. The instruction is helpful but not comprehensive.

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