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

Annotations are empty, so description carries burden. It discloses cost ($0.10), but nothing about idempotency, caching, or data freshness. For a simple read operation, this is somewhat adequate but missing key behavioral traits.

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 sentences: first describes output, second notes cost. No redundant words, front-loaded with core purpose.

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?

Given only 1 parameter and no output schema, the description is adequate but could detail return format or limitations. It covers the essential output but leaves some context implicit.

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?

The schema covers 100% of parameter details (island enum). Description does not add further meaning about the parameter, so baseline 3 is appropriate.

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 'Wave height, period, direction + 3-day forecast' clearly states the data provided. The tool name 'get_surf_conditions' matches, and it distinguishes from siblings like 'get_weather' or 'get_ocean_safety' by specifying surf-specific metrics.

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?

No guidance on when to use this tool versus alternatives such as 'get_weather' or 'get_ocean_safety'. The description only mentions cost, not context or exclusions.

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