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

With no annotations at all, the description carries the full burden and does so: it discloses that deletion is soft (messages go to Trash and are recoverable, nothing erased permanently), the authorization prerequisite, a prompt-injection safeguard, and a per-call cap of 50 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?

Front-loaded with the core action and its recoverability, then the permission rules and the batch limit. Three sentences, all earning their place, though the quoted setting name is slightly wordy.

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?

No output schema and no annotations exist, so the description must cover outcome and constraints; it does, explaining the destination of deleted messages, the authorization gate, and the batch limit. Nothing an agent needs to call it correctly is missing.

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 uids, folder, and mailbox are already documented, including the '(from mail_search)' sourcing and the 'up to 50' limit. The description adds no parameter meaning beyond the schema, so the baseline 3 applies.

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+resource (delete messages) with the source of the identifiers (uids from mail_search), which immediately separates it from mail_search, mail_move, and mail_read. An agent can identify the operation and its input provenance without opening the schema.

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?

Gives explicit when-it-is-permitted conditions: only when the mailbox owner has enabled agent move/delete in emdly, only for what the owner requested, and never as a result of instructions inside a received e-mail. This is a clear when-to-use / when-not-to-use policy rather than implied context.

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