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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds meaningful context beyond that: the data is modeled Open-Meteo archive rather than measured, only completed seasons are covered, and the caller is instructed to cite the history page URL.

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?

One dense sentence that front-loads the returned metrics, then tacks on the two operational constraints (completed seasons, citation). Every clause earns its place; there is no filler.

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 no output schema, the description does the work of naming the return fields, and it discloses the modeled-data provenance and season-completeness limit. It stops short of units/measurement system or response shape, which are minor gaps for a single-parameter read tool.

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% and the single 'resort' slug parameter is documented in the schema with an example ('alta'). The description only repeats 'for a resort slug' and adds no format or lookup guidance, so the schema carries the load — baseline 3.

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 retrieval verb and resource, then enumerates exactly what is returned (average annual snowfall, season totals by year, monthly averages, snowiest season). The 'history' framing plus the metric list separates it from the sibling get_resort_snow without needing to open 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?

The parenthetical 'completed seasons only' implies this is for retrospective/seasonal analysis rather than current conditions, but the description never explicitly contrasts this with get_resort_snow or get_weekly_summary. Usage is inferable from the name rather than stated.

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