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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds a genuinely useful behavioral detail beyond them: unknown slugs are surfaced in the response rather than dropped, which tells the agent how to handle partial failures. It stops short of describing the shape of the returned comparison facts.

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 short sentences with no filler, and the core capability is front-loaded ahead of the error-handling note. Every clause carries information an agent needs.

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 a single required parameter, full schema coverage, and rich annotations, the definition covers invocation and partial-failure behavior well. Since there is no output schema, 'side-by-side facts' is a slightly thin account of what is actually returned, which is the only remaining gap.

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% and the schema already encodes minItems 2 / maxItems 4 plus the slug array type, so the description's '2-4 drinks by slug' restates rather than extends it. No added detail on slug format or case sensitivity beyond what the schema provides.

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 resource (drinks), a specific output framing (side-by-side facts), and a bounded scope (2-4 drinks by slug), which cleanly separates it from the single-drink get_drink and the lookup siblings. It does not explicitly name those siblings, so the differentiation is inferable rather than stated.

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?

The 2-4 slug comparison framing implies when to reach for it, but there is no explicit when-to-use/when-not language and no pointer to find_drinks or search_drinks for resolving slugs first. An agent can infer the use case but must do the routing work itself.

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