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

With no annotations provided, the description carries the full disclosure burden and delivers: it warns that messages inside the folder are deleted too and that Outlook does not unfile them first — a non-obvious destructive consequence. The confirmation requirement also signals irreversibility, exactly the context an agent needs before invoking a delete.

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 sentences with no filler. The one-line purpose is followed immediately by the front-loaded WARNING about message deletion, then an actionable precondition. Every sentence earns its place.

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 2-param destructive tool with no output schema, the description covers the critical context: destructive scope, platform behavior, and the confirmation protocol. The only gap is that folderId provenance is never referenced, and there is no note about what a successful deletion returns.

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 exactly 50%: mailbox is well documented in the schema (email format, pointer to list_authorized_mailboxes), but the required folderId has no schema description and the tool description adds nothing about it. At this coverage level the description should compensate by explaining where folderId comes from (e.g., list_mail_folders); it doesn't, leaving a required parameter opaque.

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 ('Delete a mail folder') with no ambiguity. The operation is inherently distinct from sibling tools like create_mail_folder, rename_mail_folder, and merge_mail_folders, and no sibling performs folder deletion.

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?

Provides clear procedural guardrails for a destructive tool: move messages worth keeping out beforehand and ask the user for confirmation before calling. It doesn't name explicit alternatives or when-not-to-use cases, but the precondition and confirmation requirement give the agent a solid usage protocol.

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