fs_create_file

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

With no annotations provided, the description carries the full disclosive burden. It goes beyond the name by revealing that creation is refused for existing paths and that external agents will trigger a user-approval prompt. This is strong behavioral context, though it does not mention edge cases like missing parent directories or partial write behavior.

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 compact and well front-loaded: the core action is in the first sentence, the key caveat is second, and the approval prompt is last. Every sentence earns its place without redundancy.

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 two-parameter tool with an output schema and low complexity, the description covers the essential behavior: create new file, refuse existing, use fs_overwrite alternatively, and expect user approval. Minor unspecified details like parent directory handling are not critical for correct invocation.

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 must compensate. It adds meaning by specifying that content is UTF-8 and that the path must be a non-existing target path. However, it does not clarify path format, semantics, or constraints beyond existence, so compensation is only partial.

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 opens with a specific verb and resource: 'Create a new file with the given UTF-8 content.' It also distinguishes itself from the sibling fs_overwrite by explicitly stating this tool refuses existing paths, so an agent can immediately tell which tool to pick.

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?

Usage guidance is explicit: 'Refuses if the path already exists — use fs_overwrite (T2) to replace an existing file.' This states both the limiting condition and the correct alternative, leaving no ambiguity about when to choose this tool versus its sibling.

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