List Unread Messages

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

No annotations are present, so the description carries the full burden of behavioral disclosure. It reveals pagination but does not state whether the tool is read-only, whether it marks messages as read, what fields are returned, or how it handles empty results or invalid folders. 'Quick' is too vague to substitute for concrete 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?

The description is a single focused sentence with no redundant detail. It front-loads the primary action and resource, then notes pagination. Every word earns its place, aside from the mildly subjective 'Quick,' which is not harmful.

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?

This is a simple listing tool with all parameters documented in the schema, which helps. However, without an output schema or annotations, an agent still lacks clarity about what a listed message contains and whether any side effects occur. The description is minimally viable but leaves meaningful gaps.

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 schema already documents limit, folder, and offset meaning. The description adds only the word 'pagination,' which aligns with offset/limit but provides no additional semantic value beyond the structured schema.

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 identifies the verb ('listing') and resource ('unread messages'), and mentions pagination. It is distinguishable from siblings like fetch_email or get_email_body, though it does not explicitly name those alternatives.

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 phrase 'Quick listing of unread messages' implies the tool is for lightweight enumeration of unread items, and pagination hints at large-result scenarios. However, it gives no explicit guidance about when to choose this over search_emails, fetch_email, or get_email_headers, nor any exclusions.

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