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

No annotations are provided, so the description carries the full disclosure burden. It usefully reveals the fixed catalogue size (239 stations) and the default zero-argument behavior, but says nothing about whether results are paginated, how matching is done (partial match/prefix), or what a populated response 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?

Three short sentences with the resource and catalogue size front-loaded, then per-parameter guidance, then the default case. No filler and nothing an agent must read past to reach the essential facts.

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?

For a simple two-optional-parameter lookup tool with no annotations and no output schema, the description covers purpose, parameter usage, and the no-argument fallback. Only the shape of the returned station records is left implicit, which is a minor gap.

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 coverage is 100%, so both parameters are already documented in the schema, including the 2-character code form (e.g. TK). The description adds place-name examples and the joint omission behavior, but it does not explain matching semantics or whether the two parameters combine as AND or as alternatives.

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 (find tide stations) and quantifies scope (239 locations in the JMA tide table), which lets an agent distinguish it from data-returning siblings like get_tide or next_tide. It does not, however, explicitly name those siblings as alternatives.

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?

Explains how each parameter selects results (place name → query, region → region) with concrete examples, and says what happens when both are omitted (region list with station counts). That is clear usage context, but there is no explicit 'use this instead of get_tide when…' routing guidance.

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