list_folders

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

No annotations exist, so the description carries the full burden. 'List' implies a read-only operation, but the description says nothing about permissions/auth requirements, behavior on invalid folder ids, pagination, or whether hidden folders affect the default result beyond the parameter name. It is adequate but thin for a tool with zero annotation coverage.

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 compact sentences: purpose first, conditional behavior second, cross-tool vocabulary hint last. No filler, and the most decision-relevant information is front-loaded.

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 two-parameter, optional-params listing tool with no output schema, the description covers purpose, conditional scope, and accepted id vocabulary. Only the lack of any behavioral notes (auth, error handling, pagination) keeps it from being fully complete given the absence of annotations.

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 coverage is 100%, so both parameters are already documented, but the description adds the enumerated set of well-known folder names (inbox, drafts, sentitems, deleteditems, junkemail, archive) that can be passed as parentFolderId, which is meaning the schema only gestures at.

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 ('List mail folders') and immediately clarifies the scope split: no parentFolderId returns top-level folders, with it returns children. That is a concrete, distinguishing purpose no sibling tool shares.

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?

The description makes the selection rule explicit for the one real choice (top-level vs. child listing) and notes that well-known names are usable as folder ids elsewhere. It gives no guidance on when to prefer this over other listing tools, but the alternatives (list_messages, list_attachments) target different resources, so the risk of misuse is low.

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