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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds meaningful behavior in 'visible' (results are permission-filtered, so an empty listing may not mean an empty folder) and 'direct child' (depth-1 only). It says nothing about pagination behavior despite limit/offset being present, nor about ordering of results. That is a modest contribution beyond annotations, so a 3.

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?

A single front-loaded sentence with no filler; the scope qualifiers ('visible,' 'direct child') come before any other content. Nothing could be cut without losing information.

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?

An output schema exists, so return values need not be explained, and the operation is simple with only one required argument. What remains missing is pagination and ordering guidance tied to limit/offset. For a three-parameter read tool, an output schema plus annotations mean the remaining gap is small.

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 0%, so the description carries the full burden for all three parameters, yet it only gestures at folder_hash via the word 'folder' and says nothing at all about limit or offset. An agent gets no guidance on default page size, maximum of 200, or how to paginate through large folders. The gap is significant for a listing tool where pagination is the main operational concern.

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 gives a specific verb (List) and a precisely scoped resource: 'visible files and direct child folders in a Files.fm folder.' The word 'direct' usefully signals non-recursive listing, which separates it from a recursive walk or a search. It does not explicitly name distinguishing siblings like filesfm_get_folder_info or filesfm_search_files, so it falls short of a 5.

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?

It never states when to choose this tool over alternatives such as filesfm_get_folder_info (metadata) or filesfm_search_files (querying), nor does it mention prerequisites like needing a valid folder hash or read permission. Usage is only inferable from the tool name and the word 'List.'

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