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

Annotations already declare readOnly/non-destructive/closed-world, so the safety profile is covered. The description still earns credit by disclosing return semantics that matter operationally — folder paths, file counts, plan usage, and that returned ids are the handles other folder tools consume. It stops short of noting pagination or result-size limits for large accounts.

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 short sentences, front-loaded with what is returned, then the optional-scope rule, then the sequencing hint. No restatement of the name or title, no filler.

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 one-optional-param read tool with full annotation coverage and an output schema, the description covers everything an agent needs: scope behavior, returned inventory, and its role as the entry point for id-dependent folder operations.

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% and documents the 'root' alias, so baseline is 3. The description adds behavioral meaning: omitting folderId targets the root's files while the folder listing is returned regardless, clarifying that this is an optional scope selector rather than a required filter.

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?

Specific verb plus resource ('List the account's storage') with an explicit inventory of what comes back: every folder with full path and file count, plus files in one folder. This clearly separates it from the mutation siblings (move_file, delete_folder, update_folder) without needing to name them.

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?

Gives an explicit parameter-based branch ('Omit folderId to list files sitting at the root') and an explicit sequencing rule ('Start here before moving, renaming or deleting anything — the ids it returns are what the other folder tools take'). That is when-to-use plus dependency on siblings, stated outright.

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