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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: the search key is scoped server-side to Alt's live auction pool and the result set excludes other-source auctions and fixed-price items. It doesn't discuss pagination limits, but an output schema exists.

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 with zero waste. The scoping constraint (Alt's own live auctions) is front-loaded, and the contrast with alt_search follows immediately.

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 annotations covering safety and an output schema covering return shape, the description supplies what's needed to select and invoke correctly: the scope and the sibling contrast. Only minor gaps remain (e.g., pagination behavior), which are not critical here.

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 schema already documents all six parameters including the q, sort, category, and grading_company semantics. The description adds no parameter-level detail beyond that, which is the expected baseline when the schema does the heavy lifting.

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 (Search) and a precisely scoped resource (Alt's own currently live 24/7 auctions), then immediately distinguishes it from the sibling alt_search by naming what it will not return. An agent can tell it apart from alt_search without opening either schema.

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?

Explicitly names the alternative (alt_search) and the distinguishing condition: this tool never returns other source houses' listings or Alt's own fixed-price items. The routing signal is clear, though it doesn't spell out the inverse case (when to prefer alt_search instead) in so many words.

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