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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description's job is added context — and it delivers: exact returned fields per model per local day, why there is no hourly data, the conditional `sea_state` block and its Hs/Hmax/period/direction contents, and the regional-replaces-global model selection rule.

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 tight paragraphs, front-loaded with the core purpose and the most decision-relevant constraint (not hourly) before the conditional sea-state and model-selection details. Slightly verbose in enumerating every returned field, but each paragraph earns its place.

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 compensates well by enumerating the return payload per model per local day. The main gap is the unexplained `days` parameter and no note on defaults/max range for it, which matters for a forecasting 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 0%, so the description must carry parameter meaning and it only partially does. It explains `models` (force specific keys, list first) and `include_sea_state` (triggers the sea_state block, sea points only), but `days` — which controls how many daily summaries come back — is never mentioned, leaving a required-to-understand knob undocumented.

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+resource (daily weather summary for a point) and immediately scopes it: multi-model, per-local-day, not hourly. An agent can distinguish it from get_marine_bulletin, get_tide, and get_storm_risk 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?

Explicitly routes the agent: for hourly data follow `solano_url`, and before forcing `models`, call `list_models_for_location` to see what exists at the location. That is concrete when-to-use guidance referencing a sibling tool. It lacks an explicit 'don't use this for...' exclusion, so not a full 5.

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