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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds the prerequisite of resolving the ID first, which is behavioral context beyond annotations. No contradiction with annotations.

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, no fluff. The purpose is front-loaded, and the ID requirement is stated clearly. Slightly repetitive with the schema description but overall efficient.

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 tool with complete schema and annotations covering safety, the description captures the key gotcha (ID vs human name). It doesn't address edge cases like invalid IDs or return format, but given the tool's simplicity and the absence of an output schema, this is sufficient.

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%; both parameters have detailed descriptions. The description reinforces the folder_id requirement but adds no new meaning beyond what the schema already states. Baseline 3 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?

States a specific verb and resource: 'Get one exact Gmail/Outlook/IMAP folder.' It explicitly distinguishes from listing by saying 'one exact,' and contrasts with email_list_folders and email_resolve_folder. The purpose is unambiguous and differentiates from siblings.

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 explicit step-by-step guidance: 'Resolve folder name -> folder.id first' and 'Obtain with: email_list_folders -> folder.id.' It also gives a clear exclusion: 'Never pass: human folder name such as Inbox when an ID is required.' This fully covers when and how to use the tool.

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