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

Annotations already declare non-read-only, non-destructive, non-idempotent. Description adds key behaviors: short-lived, bound to order, PUT method, allowed types/sizes, 1GB per order. No contradictions.

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?

Two sentences, front-loaded with purpose and prerequisite, second sentence covers all needed steps and constraints. No extraneous information.

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?

Covers purpose, prerequisites, steps, constraints, and integration with sibling tool. With output schema present, no need to detail return format. Provides all necessary context for correct invocation.

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 coverage 67% but description compensates: explains how filename and size are used, adds file type and size constraints. The POST-upload integration with submit_brief clarifies the key output.

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?

Clearly states the tool gets a short-lived presigned URL to upload one brand-asset file. Verb 'Get' and resource 'presigned URL' are specific. Distinguishes from sibling tools like create_checkout or submit_brief by focusing on upload.

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 prerequisite (order_token from get_order), steps (PUT file then reference key in submit_brief), and constraints (file types, sizes, per-order limit). Provides clear context for when to use vs alternatives.

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