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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds non-obvious behavior: results are drawn from the catalog, only the single best bottle is returned, and there is no commerce/purchase path. It does not describe pagination 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-loads the trigger condition before the mechanics, which is the right ordering. Most sentences earn their place, though the kind/bottle guidance overlaps with the schema's own description and could be tightened.

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 an output schema present, return values need not be explained, and the description covers trigger, parameter routing, and a scope boundary. Given four parameters and enum semantics, this is nearly complete; only the limit parameter 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 coverage is 75%, so most parameters are already documented. The description still adds meaning beyond the schema by clarifying that a 'bottle' excludes juices, syrups, and garnishes, and by explaining zero_proof_only in user-intent terms. It omits any discussion of limit, leaving that entirely to the schema.

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 ('Suggest the next ingredient', 'Returns the one catalog bottle that unlocks the most drinks') and constrains scope to 'single' and 'most new cocktails from what they already have'. An agent can distinguish this from find_cocktails_from_bottles (which lists drinks rather than recommending one addition) 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 says when to use it ('when the user asks which single ingredient or bottle to add') and gives conditional routing for parameters ('Pass kind bottle when the user says bottle, spirit, liquor, or booze; otherwise leave kind as any'). Also states a negative boundary: 'It does not sell anything or link to a store.'

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