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

With no annotations, the description carries the behavioral disclosure burden. It clearly states what is returned, what is not returned (message bodies), and how to retrieve bodies. It lacks details on ordering or pagination, but for a read-only list operation the key behavior is well disclosed.

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 tightly written sentences: the main purpose and output are front-loaded, the key limitation is stated next, and parameter guidance follows. 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?

For a simple list tool without an output schema, the description covers purpose, return fields, limitations, and relevant alternatives. It lacks explicit mention of ordering or pagination behavior, but this is a minor gap given the tool's low complexity.

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 reinforces the meaning of `search` and `folder` but adds little beyond the schema's own parameter descriptions; `limit` and `account` are not elaborated further.

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 states a specific verb and resource ('List email conversations') and enumerates the returned fields: subjects, participants, dates, and a snippet. It also explicitly distinguishes itself from email_get_message_body by clarifying that it does not return message bodies.

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 gives explicit when-to-use guidance: use email_get_message_body when a snippet is insufficient, and use `search` and `folder` to find or scope threads. This clearly routes an agent to the right operation and parameters.

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