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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the mutation/safety profile is covered. The description adds a useful constraint about the email-sender folder type, but says nothing about permissions, duplicate-name behavior, or what happens when workspace_id is omitted (beyond what the schema states).

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?

Two short sentences with the actionable content first. Minor waste in the redundant 'Create a Folder - Create a new folder' opening, which repeats the title and name.

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 low-complexity, 3-parameter tool with full schema coverage and an output schema, the description covers the essential caveat (folder type scoping). Only the absence of selection guidance against sibling create_* tools keeps it from being complete.

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 the baseline is 3. The description restates the 'type' field restriction that the schema already documents verbatim, adding no syntax, format, or constraint details beyond it.

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 ('Create a new folder for organizing items'), so an agent immediately knows the operation. It does not explicitly contrast with siblings like get_all_folders or create_list, but the resource is distinct enough within the toolset.

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 never says when to use this tool versus alternatives (e.g., create_list, create_workspace) or what prerequisites exist (workspace selection, permission requirements). The only conditional guidance concerns the 'type' field, which is parameter behavior rather than tool-selection guidance.

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