eda_sys_file_system_get_extension_file

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

No annotations are provided, so the description carries the full burden. It only restates the signature and return type; it does not disclose whether the operation is read-only, what URI scope is valid, how the returned File is materialized, or what happens if the file is missing. The `undefined` in the type hint is a minor implicit 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 front-loads the method signature and purpose in three short lines. The `returns` line slightly duplicates the return type already present in the signature, but overall it is tidy and free of fluff.

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 file-retrieval tool with no annotations and no output schema, an agent would need more context: what URI scope is allowed, error behavior, and how to consume the returned File object. The description provides only a skeletal call contract and leaves significant operational details implicit.

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 only provides a generic `args` array description, so the signature adds meaningful parameter semantics by specifying a single `uri: string` parameter and its order. It still does not describe URI format, path rules, or acceptable values, which keeps it from a 5.

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 states the concrete operation '获取扩展内的文件' (get file within extension) and provides the full signature `sys_FileSystem.getExtensionFile(uri: string) -> Promise<File | undefined>`, naming both the resource and the return type. It does not explicitly contrast with sibling file-system helpers, so it stops 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?

There is no guidance on when to use this tool versus related alternatives like read_file_from_file_system, list_files_of_file_system, or the file dialogs. The signature implies a URI argument, but the description gives no context, exclusions, or alternative routing.

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