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

Annotations declare readOnly/idempotent/openWorld, so the safety profile is covered. The description adds real operational context beyond annotations: it cannot ingest chat attachments, it resolves supported public links itself, and results are region-aware retailer/resale listings with verified prices and buy links. It does not state rate limits or failure modes, so it stops short of a 5.

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?

Front-loaded with the core requirement and the alternative tool, which is good. However, the attached-photo fallback is a long run-on sentence that packs tool-routing, extraction instructions, and result-presentation rules into one clause chain, making it harder to parse than necessary.

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?

An output schema exists so return values need not be described, yet the description still usefully summarizes the return (region-aware retailer/resale listings, images, prices, buy links). Combined with usage rules and the attachment limitation, an agent has enough to call correctly; only the link-vs-image_url precedence is left implicit.

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 description coverage is 100%, so the schema already documents link, image_url, region, and max_results including formats and bounds. The description adds the constraint that a visual source is required and that links are resolved by Remode, but it does not explain parameter interplay (e.g., link vs image_url precedence). Baseline 3 is appropriate.

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 states a specific verb+resource ('identify, visually match, or shop' fashion from a visual source) and explicitly distinguishes itself from the sibling find_fashion_by_description. The requirement of a visual source is front-loaded and unambiguous.

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 when-to-use ('user has supplied a photo, screenshot, direct image URL, social post, blog, or product page'), when-not ('concrete text-only product request' → use find_fashion_by_description; 'styling advice, garment care, outfit ratings, non-fashion products' → do not use), and it handles the attached-file edge case with a concrete fallback path.

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