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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description earns credit beyond that by disclosing 'source health' on each entry and by disclaiming that links are not live shelf-stock, delivery-coverage or price checks and that a listed venue does not prove current stock.

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, both load-bearing: the first states the return contents, the second carries the caveats and the parameter scope. Front-loaded and free of filler, though the caveat clause is dense enough to need a second read.

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, so the description must describe results, which it does (retailer destinations, venues, source health). Combined with annotations covering the safety profile, an agent has what it needs to call this correctly; only the per-entry shape of 'source health' remains unspecified.

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 0% and the sole parameter is generically named 'query', which would otherwise read as full-text search. The description clarifies it is optional and filters physical venues only, a meaningful constraint the schema does not convey.

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 uses a concrete verb and resource: it returns online retailer buying destinations plus verified UK venues, each with source health. That is specific enough to distinguish it from browse_beers or get_product, though it never names a sibling to route the agent explicitly.

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 implied ('where to buy') and the description warns that results are not live stock or price checks, which shapes expectations. It never says when to prefer this over compare_alternatives or open_shop, so the agent must infer the boundary.

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