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

Annotations already declare the write/openWorld/non-idempotent profile. The description adds real context beyond them: accepted formats, the 25 MB cap, and the retention rule that never-ordered pictures are deleted after 30 days.

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?

Three short sentences with zero filler, leading with the action, then constraints, then the retention caveat. Every sentence carries information an agent needs.

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?

No output schema exists, and the description covers what is returned (pixel dimensions and printable size) plus inputs and limits. Failure modes (bad link, oversized file, unsupported format) are not described, a minor gap for a nested-parameter intake tool.

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 baseline is 3, but the description adds constraint semantics the schema lacks: which formats are accepted and the 25 MB limit, plus it maps 'a public http(s) link' to image_url and 'an attached file' to file.

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 specific actions and resource: fetch from link or attached file, store it for a design, and report pixel size plus print size. Clear verb+resource, but it never mentions how it relates to siblings like create_design, so differentiation is left to the agent.

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?

Usage is only implied: the agent can infer this is the intake/validation step for a picture before a design is created, and the two input modes are named. There is no explicit when-to-use, when-not, or pointer to an alternative sibling.

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