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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered and the description does not need to restate it. The word 'visible' adds a genuine behavioral constraint about access scoping, but nothing is said about what happens for non-visible or unknown files (error vs empty result).

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, and the object of the operation is stated before any qualifiers. Slight redundancy in repeating the 'Files.fm' brand that already appears in the tool 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?

An output schema exists, so return values need not be described, and a one-parameter read tool is inherently simple. However, the sole required input is entirely unexplained and there is no hint on sourcing a file hash, leaving an agent unable to invoke it without guessing.

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% for the single parameter, file_hash, and the description does not compensate at all - it never says what a file hash is, its format, or how to obtain one. With the structured field bare, this is the definition's largest gap.

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 ('Return metadata') against a specific resource ('one visible Files.fm file'), which cleanly distinguishes it from siblings like filesfm_read_file (content) or filesfm_list_folder (enumeration). It stops short of naming an alternative explicitly, so it is clear but not fully differentiated.

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?

There is no when-to-use or when-not-to-use guidance and no alternatives named, even though siblings such as filesfm_get_doc, filesfm_search_files, and filesfm_read_file overlap in scope. The only implied usage is that the agent already has a file reference.

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