filesystem-mcp-server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the default recursive behavior for directories, which is useful, but lacks critical details such as permission requirements, error handling (e.g., what happens if source doesn't exist or destination already exists), side effects, or whether it overwrites files. For a mutation tool with zero annotation coverage, this is a significant gap.

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?

The description is concise and front-loaded, with two sentences that efficiently convey the core action and a key behavioral trait. There's no wasted text, though it could be slightly more structured (e.g., separating purpose from guidelines).

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?

Given the complexity of a file system mutation tool with no annotations and no output schema, the description is incomplete. It lacks information on permissions, error conditions, return values, and how it interacts with sibling tools. The description alone doesn't provide enough context for safe and effective use.

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?

The schema description coverage is 100%, so the schema already documents all parameters thoroughly. The description adds minimal value beyond the schema by reiterating that paths can be relative or absolute and noting the default recursive behavior, but doesn't provide additional syntax, format, or semantic details. Baseline 3 is appropriate when the schema does the heavy lifting.

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 clearly states the tool's purpose: 'Copies a file or directory to a new location.' It specifies the verb ('Copies') and resource ('file or directory'), but doesn't explicitly differentiate from sibling tools like 'move_path' or 'write_file' beyond the inherent meaning of 'copy' versus 'move' or 'write'.

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 provides some implied usage context by mentioning 'Defaults to recursive copy for directories,' which suggests when to use default behavior. However, it doesn't explicitly state when to choose this tool over alternatives like 'move_path' or 'write_file,' nor does it mention prerequisites or exclusions.

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