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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the basic write-but-not-destructive profile is covered. The description adds useful context about organizing uploaded files, but it does not disclose behaviors like duplicate-name handling, ID generation, or return values. That is acceptable but not exceptional given the 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?

Two sentences, no filler. The primary action is front-loaded, and the second sentence provides a valuable routing pointer to update_folder without wasting words.

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 two-parameter create tool with full schema coverage and non-destructive annotations, the description is sufficient. It clearly states the purpose, covers the main alternative, and no critical missing context blocks invocation. A small gap is the absence of return-value or duplicate-handling guidance, but this is not severe for such a straightforward tool.

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 input schema already fully documents 'name' and 'parentid'. The description adds marginal conceptual context through 're-parent' but does not meaningfully enhance parameter understanding beyond the schema.

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 uses a specific verb and resource ('Create a new folder') and adds purpose context ('organising the business's uploaded files and documents'). It also distinguishes itself from update_folder by explicitly reserving rename/re-parent operations for that sibling.

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 states exactly when to use this tool (creating a new folder) and gives an explicit alternative for existing folders: 'To rename or re-parent an existing folder use update_folder instead.' This leaves no ambiguity about tool selection.

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