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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety and idempotency are covered. The description adds genuinely useful behavior beyond that: stale records are marked, expired/missing/far-future data is unavailable, point samples are distinct from accumulated intervals and window totals, and coverage gaps should be checked. That is solid added context, though it remains telegraphic about what a partially-covered response actually looks like.

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?

Front-loaded with the core action and free of filler; nearly every clause carries operational meaning. It is somewhat dense and telegraphic in places ('Stale is marked; expired, missing and far-future data is unavailable'), and the output-semantics sentence sits awkwardly between parameter guidance.

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 an output schema present, return-value detail is unnecessary, and the description still covers staleness, unavailability windows, coverage checking, and the sibling alternative. An agent has everything needed to choose this tool and 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 description coverage is 100%, so the schema already defines slug format, ISO 8601 start/end with exclusive end, view enum, and targetId omission semantics. The description reinforces the intent of start/end and targetId (bounding the response, all-targets default) but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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 and resource ('Get published weather for a peak') plus the optional target scope (summit/hut/trailhead), which no sibling provides. It also differentiates itself from get_peak by naming that tool for long-range planning.

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 says to set targetId and start/end for a bounded planning response and warns that unfiltered forecasts are large, which tells the agent when to narrow. It names a concrete alternative ('For a trip months away use get_peak seasons instead') and adds a prohibition against inventing forecasts or safety verdicts.

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