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

Annotations only declare the generic safety profile; the description adds the substantive behavior an agent needs: the URL expires in one hour, the upload is a raw PUT with a Content-Length header, the file must already be on disk, and there are pixel/size limits. Cost ('Free') and the prohibition on deceptive use are also disclosed.

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 operational sentence is front-loaded and dense with useful detail; the policy sentence is long but carries real constraint value. Slight verbosity in the lawful-use enumeration keeps it from a 5.

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?

With an output schema present, return values need no explanation, and the description still covers preconditions, upload mechanics, chaining to make_receipt, limits, and cost. An agent has everything required to call it correctly.

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 is 100%, so the baseline would be 3, but the description adds constraints absent from the schema — the 2-megapixel cap for PNG/JPEG and the fact that the source file lives on disk. It still doesn't explicitly say that 'bytes' must match the real file size, leaving one inference.

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?

States a specific verb and resource — 'Get a one-hour signed upload URL for a logo file' — plus the accepted formats and size limits, so the agent knows exactly what the tool produces. It also links the output to make_receipt's logo.file_id, distinguishing it from its siblings.

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?

Gives an explicit downstream workflow ('PUT the raw bytes to upload_url ... then pass file_id as make_receipt's logo.file_id') and a policy boundary on lawful use. It does not name any sibling alternative or exclusion condition, but no true alternative exists among the listed tools.

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