Assets Create Upload Url

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

Annotations already indicate this is not read-only and not destructive, but the description adds valuable behavioral details: the need to PUT raw bytes to the returned `uploadUrl`, the Content-Type requirement, and the 5GB max size. This goes beyond the annotations and helps the agent understand the expected action and constraints.

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 concise and well-structured: two sentences front-load the core purpose and then provide necessary follow-up steps. Every sentence earns its place, covering purpose, usage, and constraints without fluff.

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?

Given the simple 3-parameter schema and no output schema, the description is remarkably complete. It explains the two-step upload process, names the companion tool, and mentions the return fields (`uploadUrl` and `url`) that the agent will need. No critical information appears missing.

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 schema has 0% description coverage, so the description must compensate. It does add context: 'local file' refers to `fileName`, 'same Content-Type' maps to `contentType`, and 'Max 5GB' relates to `size`. However, it doesn't explicitly define units (e.g., bytes vs MB) or specify whether fileName should include extension, leaving some ambiguity.

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's specific purpose: 'Upload step 1: get a presigned URL for a local file.' It uses a specific verb ('get') and resource ('presigned URL'), and distinguishes itself from the follow-up tool `assets_create`. The workflow is immediately understandable.

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?

Explicit guidance is given: 'Use this when your media is not already at a public URL.' This directly tells when to use this tool versus alternatives, and also implies the alternative (skip this step if media is already public). It even explains the full sequence with `assets_create`.

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