list_new_emails

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

With no annotations, the description carries the load and does well: it discloses the non-obvious side effect that automated senders are skipped and auto-marked processed, that results are oldest-first, and that only metadata is returned. It omits rate limits or whether listed emails themselves get marked processed, keeping it below a 5.

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 tight sentences: purpose first, return shape second, side-effect caveat third. No filler, and the important behavioral detail is front-loaded.

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?

An output schema exists so the return shape needn't be described, and the description still adds useful semantics (auto_skipped). The main omission is the meaning of 'top' and any paging behavior, which an agent needs to call it correctly.

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?

The single 'top' parameter is undocumented in the schema (0% coverage) and never mentioned in the description, so an agent gets no guidance on the page size, its default of 10, or how to retrieve more results. This is the clear gap in an otherwise strong definition.

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 and resource plus the defining filter (unprocessed) and ordering (oldest first), which cleanly separates it from get_email and the other siblings. An agent can tell exactly what this returns.

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 routes the agent to get_email for message bodies, which is the key next-step decision. It gives clear context for use but does not name when-not-to-use cases (e.g., after mark_processed or when paging).

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