files_upload

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the agent knows this performs a write operation. The description adds the return format {success, file}, which is helpful given there is no output schema, and mentions supported content encodings.

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 a single sentence, front-loaded with the action, followed by the return format. Every word adds value, with no repetition of schema details or annotations.

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 upload tool, the description combined with the fully documented schema covers the purpose, parameter usage, and return value. It omits edge-case behavior like overwriting existing files, but this is not critical for basic usage and the destructiveHint=false annotation implies no destructive overwrite.

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 input schema provides 100% coverage with descriptions for all four parameters, including the base64 flag and content_type. The description does not add new parameter semantics beyond what the schema already explains, so the baseline score of 3 is appropriate.

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 the specific verb 'Upload' with the resource 'file', and clarifies accepted content formats (UTF-8 text or base64 binary). This clearly distinguishes it from sibling tools like files_list and files_get, which perform read operations.

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 clear context for when to use the tool: to upload a file. No alternatives to uploading exist among siblings, so explicit exclusions are unnecessary, making this clear enough for an agent to select it.

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