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 real contribution is disclosing the access model: free within a daily allowance, then $0.001 USDC per call via x402. That payment/access requirement is exactly the kind of behavioral context annotations cannot express.

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?

Two short sentences with no waste, and the functional content is front-loaded before the pricing note. The opening is a noun-phrase fragment rather than a full statement, which is a minor structural weakness but not verbose.

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 values need not be explained, and annotations carry the safety semantics. The description covers purpose and cost, leaving only the absence of sibling-routing guidance as a gap, which is already accounted for under usage guidelines.

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 'station' parameter is documented in the schema as a NOAA CO-OPS station id. The description adds no syntax, format, or example beyond the schema, so the baseline of 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?

The description enumerates what the tool returns for a station (location, time zone, products offered, tidal datums), which clearly identifies it as a station-metadata lookup. Combined with the title it is unambiguous, but it never states a verb and does not distinguish itself from siblings like tides__search or tides__stations-near.

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?

There is no when-to-use guidance, no prerequisites, and no named alternatives. The only contextual sentence concerns pricing, not selection between this and the other tides__ tools.

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