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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it is a safe, read-only operation. The description adds value by clarifying the date-scoped focus and explicitly stating that it returns only 'scheduled or confirmed' openings, not all current openings. This goes beyond the annotations to set proper expectations, though annotations already cover the safety aspects well, so a 4 is appropriate.

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?

The description is relatively concise—a few sentences—and front-loaded with the main purpose. However, the last sentence is somewhat long and could be broken into clearer usage guidance, making it slightly less crisp than ideal. Still, every clause adds value, so a 4 is reasonable.

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?

Given that the tool has 4 parameters with full schema coverage, annotations that cover safety/idempotency, and an output schema (so return format is documented elsewhere), the description covers the core logic well. It does not need to explain return values. It could add a note about the date default behavior more explicitly, but overall it is complete enough for an agent to use 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 description coverage is 100%, so the input schema already documents all 4 parameters with descriptions. The description does not add any additional parameter-level meaning beyond what the schema provides, hence a baseline score of 3 is warranted.

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?

The description is very specific: it identifies the tool as returning resorts whose opening date is a given day, clarifying exactly what it answers (e.g., 'what opens today?') and what it does not return (all currently-open resorts). This sharply distinguishes it from siblings like get_southern_hemisphere_report, achieving full clarity.

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 description explicitly states when to prefer this tool ('prefer over get_southern_hemisphere_report for opening-day questions') and when NOT to use it, providing two clear alternatives: use get_insights with category=season_calendar for ranked retrospectives, and ask_snowdata for historical norms. This gives the agent unambiguous decision rules.

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