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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real behavioral context beyond them: results are ordered most-recently-deleted-first, only restorable mail is returned, and a deleted conversation is flattened into individual messages.

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 sentences, zero filler, with the scope and default ordering front-loaded followed by the one non-obvious output-shape caveat.

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 return values need not be explained, and the description covers ordering and conversation flattening. Remaining gaps are the undocumented limit/inbox_id semantics, which the description could have shored up.

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 only 33% (only cursor is documented); limit and inbox_id carry no schema descriptions, and the tool description mentions none of the three parameters, so it does not compensate for the gap. Nothing is added about page sizing or the inbox_id requirement.

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) plus a precisely scoped resource (an inbox's deleted emails that can still be restored), and adds ordering. The word 'deleted' implicitly separates it from list_messages/list_threads, though no sibling is named explicitly.

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?

Usage is implied rather than stated: an agent can infer this is the view for trashed-but-recoverable mail, which pairs with restore_message. There is no explicit when-to-use, when-not-to-use, or named alternative versus list_messages.

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