get_upload_url

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

Annotations declare readOnlyHint=true, and the description adds behavioral context such as the return value (upload address and usage instructions) and the mode-dependent behavior. It discloses that the tool itself does not upload but returns an address, and explains the edge case where no endpoint exists.

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: a one-sentence purpose, a numbered workflow, and a brief return summary. Every sentence adds value, with no filler or redundancy.

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 zero-parameter utility, the description is complete: it explains the purpose, the exact HTTP POST usage, the expected response field (saved_path), and the follow-up calls to other tools. It also covers the local stdio mode limitation. No output schema exists, but the description adequately conveys return behavior.

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 tool has zero parameters, so the schema fully covers parameter semantics. The description doesn't need to explain parameters; it instead explains the workflow and return value, which is appropriate for a 0-param tool. Baseline 4 per instructions.

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 the tool gets an upload URL to push files to the server for recognition. It uses a specific verb+resource and distinguishes itself from sibling tools like describe_video/view_media, which process files rather than provide upload access.

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?

It explicitly outlines when to use the tool (to move files from claude.ai chat/sandbox to the server) and provides a step-by-step workflow. It also notes a key limitation (local stdio mode has no upload endpoint), giving clear usage context without ambiguity.

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