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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower, yet the description adds real operational context: fixed page size of 20, cache-hit reuse, cache-miss API request, and a room-page fallback. These are behaviors an agent cannot infer from annotations or schema, though the fallback's effect on returned data could be spelled out more.

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?

Three sentences, front-loaded with purpose then alternatives then caching mechanics. No filler, though the caching clause is slightly dense and could be trimmed without losing meaning.

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?

An output schema exists so return values need not be described. Combined with annotations, the description covers purpose, sibling routing, pagination, and caching behavior—everything needed to call it correctly.

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 1-based/default-1 note duplicates the schema. However, 'one page of 20' conveys the result-set size per page, which the schema does not express and which materially affects paging behavior.

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 ('Return one page of 20 individual public Airbnb reviews'), the resource (reviews), and the key scope constraint (for a listing ID, 20 per page). An agent can immediately tell this is listing-level review retrieval and not host-level or room-detail retrieval.

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 two relevant alternatives and the condition that selects each: 'Use this for listing-level review text; airbnb_room returns room details and aggregate rating/count, while airbnb_host_reviews returns reviews guests left for a host.' Routing is unambiguous.

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