mark_email_read

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

With no annotations, the description discloses core behavior (setting IMAP Seen flag) but could mention side effects like notifications or permission requirements. Still adds good 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?

Three sentences, front-loaded with core purpose, no wasted words.

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?

Sufficient for a simple write tool without an output schema. Includes purpose, usage, and alternative. Missing details like return value or error handling, but not critical for this action.

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 50%, hover at the boundary. Description implies isRead is a boolean but adds no extra detail beyond schema. 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 action ('mark as read or unread'), the resource ('single email'), and the mechanism ('IMAP Seen flag'). It distinguishes from siblings like batch_email_action.

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?

Explicitly provides when to use ('individual triage or to reset read state') and when not to ('prefer batch_email_action...when updating multiple emails').

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