download_file

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

The annotation readOnlyHint=true already signals a safe read operation, and the description aligns with that. The description adds value by disclosing the base64 encoding, the return structure (file_content, filename, size_bytes), and the typical file source. It goes beyond what annotations provide, making behavior more predictable.

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 well-structured with a clear one-sentence summary followed by Args and Returns sections. The return detail is necessary because there is no output schema. Every line earns its place, though the Args section could be slightly more compact without losing clarity.

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 simple 1-parameter tool with read-only annotation and no output schema, the description covers the key aspects: what it does, when to use it, what the parameter is, and what it returns. It lacks error-handling or permission notes, but those are less critical given the tool's simplicity and the sibling context.

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?

With 0% schema description coverage, the description compensates by explaining file_path as 'Local path to the file (typically from upload_file or a tool that created a file).' This adds meaningful context beyond the schema's 'File Path' title, clarifying the parameter's role and expected values.

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+resource ('Download a file from the server as base64') and immediately differentiates from siblings like upload_file by focusing on download. It also adds a clear use case (retrieve updated file content after modifications), which distinguishes it from read-oriented tools like read_cells.

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 states when to use the tool ('Use after tools that modify a workbook to retrieve the updated file content') and provides context on the file_path source ('typically from upload_file or a tool that created a file'). It does not list exclusions or alternative tools, but the usage context is clear and actionable.

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