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

No annotations are provided, so the description must carry the behavioral burden. It usefully discloses asymmetric historical limits: tides up to 365 days but weather only up to 90 days. It does not explain return format, handling of future dates, or other operational constraints.

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?

The description is two short sentences with no wasted words. The core purpose is front-loaded, followed immediately by the key historical range constraints.

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 read-only data retrieval tool with complete schema descriptions, the definition covers the essential historical scope and range limits. It could do slightly more to describe return shape or behavior for invalid past-date requests, but the high schema coverage reduces that need.

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 the schema already documents all four parameters. The description adds meaningful semantics by clarifying that the 365-day limit applies to tides while weather is capped at 90 days, which is not expressed in the schema's generic 'days' maximum.

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 states a specific verb and resource: historical tide predictions and weather data for past dates. It clearly distinguishes itself from current-condition siblings by emphasizing 'historical' and 'past dates', though it does not explicitly name get_tides or get_weather 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?

Usage is implied by 'for past dates', which helps the agent choose this over current-condition tools. However, there is no explicit when-to-use versus when-not-to-use guidance, and no direct routing to siblings such as get_tides or get_weather.

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