mark_as_read

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the mutation effect but does not mention idempotency, permanence of the read state, potential side effects, permissions, or response behavior. The 'UIDs are permanent identifiers' note adds some context but does not cover operational behavior.

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 short sentences with no filler. The primary action is front-loaded and the follow-up sentence provides meaningful context about UIDs. Every word contributes.

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, single-purpose mutation tool with no output schema, the description provides the essential context: the action, the resource, and the mechanism. It could be improved by noting reversibility (mark_as_unread exists) or the idempotent nature, but the low complexity means the current description is largely sufficient.

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 baseline is 3. The description adds semantic value by clarifying that UIDs are permanent identifiers, which helps agents understand that these are stable identifiers rather than transient session IDs. This goes beyond the bare schema descriptions of 'array of UIDs to mark as read' and 'folder containing emails'.

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 emails as read') and the resource (emails), with the mechanism ('using UIDs') and a useful clarification that UIDs are permanent identifiers. While it differentiates from mark_as_unread through the word 'read', it does not explicitly call out sibling distinctions.

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?

No guidance is given about when to use this tool versus alternatives such as mark_as_unread, flag_emails, or delete_emails. The mention that UIDs are permanent identifiers implies why UIDs should be used, but there is no explicit context or exclusionary guidance.

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