m365_mail_folders

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

Annotations already declare this as a read-only, non-destructive, idempotent operation. The description adds the expectation of counts in the output, which is a behavioral trait not covered by annotations. However, it does not disclose other behavioral details such as whether folder hierarchy is included, pagination, or performance implications. With good annotation coverage, this is sufficient for a 3.

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?

The description is a single, front-loaded sentence that directly states the tool's function without any filler. For a simple tool with no parameters, this is appropriately concise and well-structured.

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?

In the absence of an output schema, the description should clarify what the tool returns. It says 'with counts' but does not specify counts of what (e.g., messages, unread items) or any structural details (e.g., nested folders). While annotations provide safety context, the description leaves some ambiguity about the return value shape, making it incomplete for a tool with no output schema.

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 tool has zero parameters, so the schema provides complete coverage (100%). The description adds no parameter details because there are none. Following the baseline rule for 0-parameter tools, a score of 4 is appropriate.

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 clearly states the action ('List'), the resource ('all mail folders'), and adds a specific detail ('with counts'). This distinguishes it from sibling tools like m365_mail_list (which lists emails) and m365_mail_read (which reads a single email).

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?

No guidance is provided about when to use this tool versus alternatives. The description does not mention any exclusions, such as 'use m365_mail_folders when you need folder structure, not email content.' Without this context, the agent is left to infer usage from the tool name alone.

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