upload_files

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

With no annotations provided, the description carries the full burden and does so excellently. It discloses the default session lifecycle (create, upload, finalize), the non-finalizing append behavior, the contribution routing side-effect, and automatic S3 multipart for large files. These are meaningful behavioral traits not apparent from the schema alone.

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-structured: a one-sentence main purpose, then a bulleted list for session behaviors, and a final sentence for large-file handling. Every sentence adds distinct information with no redundancy, and the key use case is front-loaded.

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 tool with session management complexity and multiple mode variants, the description covers the default behavior, parameter-driven modifications, the caller's finalization responsibility, and large-file handling. The lack of an output schema is acceptable because the tool's primary effect is side-effectual (uploading files), and the description sufficiently sets expectations.

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 value by grouping parameters into session behavior scenarios (fresh session, append, contribution), giving the parameters contextual meaning beyond their individual schema descriptions. It also clarifies the caller's responsibility for finalization, which enriches the parameter semantics.

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 'Upload multiple files from the local filesystem in one operation,' which clearly specifies the verb (upload), resource (files), and scope (multiple, from local filesystem). It also differentiates from sibling tools like upload_file (singular) and create_upload_session by framing the operation as a batched, session-managed action.

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 each parameter: default for fresh session, upload_guid for appending, contribution_id for contribution routing. It does not explicitly name alternatives (e.g., upload_file for single files) or state when not to use the tool, but the parameter-specific behavior serves as strong usage guidance.

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