download_file

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

No annotations are provided, so the description carries full burden. It mentions SFTP, default local path, and warns about large files. However, it lacks details on overwrite behavior, directory creation, error handling, or authentication requirements, which are important for a file download tool.

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 three sentences and an example, all essential. First sentence states purpose, second gives usage guidelines, third is an example. No wasted words, well-structured.

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?

The tool has 3 parameters with full schema coverage, usage guidelines, and a size warning. An output schema exists, so return values need not be described. However, missing details like overwrite behavior and error handling slightly reduce completeness.

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 100%, so baseline is 3. The description adds little beyond schema: it restates default for local_path in prose and provides an example. No additional semantics for connection_id or remote_path.

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 'Download a remote file to a local path via SFTP.' This specifies the action (download), the resource (remote file), and the protocol (SFTP). It distinguishes from sibling tools like upload_file (opposite direction) and execute_command (command execution).

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 explicitly says 'When to use: Fetch logs, reports, or backups' and 'When NOT to use: Avoid very large downloads (>100MB) unless you verified size first.' This provides clear context and a size limitation, guiding the agent on appropriate usage.

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