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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety is covered. The description adds that results are price-constrained relative to the input, but says nothing about empty-result behavior, result count default, or whether the input bottle itself can appear. Adds some value over annotations, not rich.

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 tight sentences, zero waste. The result definition is front-loaded and the usage trigger 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?

For a simple read-only lookup with no output schema and full parameter documentation, this covers what the tool returns and when to call it. Only minor gaps remain (no-result handling, whether the source bottle is excluded).

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 bottle_id (UUID or name) and limit (1-10, default 5) are fully documented in the schema. The description adds no parameter-level syntax or constraints beyond what the schema already states; baseline 3 applies.

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 ('bottles ... at a lower price than the given bottle') and adds a qualifying constraint (same style, similar flavor) that implicitly separates it from find_similar. It never names a sibling, so the differentiation is inferred rather than explicit.

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 a concrete when-to-use trigger: "'what tastes like X but costs less' questions." There is no when-not guidance or explicit routing to compare_bottles/find_similar, but the trigger is clear enough to select the tool.

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