list_emails

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

readOnlyHint=true already establishes this is a safe read, so the bar is lower. The description adds useful behavior the annotation does not: results are oldest-first and paging is cursor-based. It says nothing about default page size behavior beyond the schema, total counts, or what fields come back.

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?

One sentence, front-loaded with the verb and resource, then scope, ordering, and pagination. Nothing is wasted and nothing important is buried.

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 read-only list tool with fully documented params and no output schema, the description covers resource scope, ordering, and paging style. Minor gaps remain around return shape and whether other filters (e.g., status, domain) are intentionally absent.

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 coverage is 100%: after, before, and limit are all documented in the schema, including the mutual exclusivity of after/before and the 1-100 range. The description's mention of cursor pagination and oldest-first ordering reinforces the semantics but adds no syntax the schema lacks, so baseline 3 is correct.

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?

States a specific verb (list) and resource (the team's transactional emails), plus the states included (sent, queued, scheduled). It does not distinguish itself from near-siblings such as mailbox_list_messages or list_broadcasts, so it stops short of a 5.

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 description implies when it applies (you want the team's transactional email set) and mentions ordering and pagination, but gives no explicit when-to-use versus mailbox_list_messages, list_broadcasts, or list_templates, and no exclusions.

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