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

Annotations already declare readOnlyHint and openWorldHint, so the bar is lower; the description adds real context: 2-night Fri–Sun window, roughly 6–8 weekend horizon depending on mode, and that results are ordered cheapest first. It doesn't describe error or empty-result behavior, but the pricing scope and ordering are well disclosed.

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 dense sentences, front-loaded with the core action and ending with the ordering guarantee. No filler or repetition of the title.

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 read-only pricing query with no output schema, the description covers scope, both input modes, time horizon, and sort order. Minor gap is what the returned price entries actually contain, but the essential calling information is present.

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%, so baseline is 3, and the description goes further by explaining the hotel_id vs city relationship (city is used when hotel_id is omitted) rather than just restating field names. Currency behavior is left to the schema, which already covers it.

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?

Specific verb (prices) plus resource (upcoming Fri–Sun 2-night weekends) and an explicit goal (find cheapest times to stay). An agent can distinguish it from get_live_rates and search_stays without opening any 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?

Clearly states the two modes: pass hotel_id for one hotel (~8 weekends) or a city to compare curated stays (~6 weekends), including the specific cities. It doesn't explicitly exclude sibling tools like get_live_rates, but the conditions for each mode are concrete.

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