fetch_era5_land_soil_moisture

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

No annotations are provided, so the description carries the full burden. The description only says 'Downloads' and does not disclose potential side effects like network dependency, overwriting existing files, required API credentials, or failure modes. It adds no behavioral context beyond what the tool name and schema imply.

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 sentences, front-loaded with the action verb and resource. There is no redundant or filler content. Every sentence 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?

The description provides a clear purpose and usage context, and the schema is comprehensive. However, it lacks any note about prerequisites (e.g., CDS API key, network availability) or potential pitfalls, which would be important for a data download tool. Given the schema and output schema, this is a decent but not fully complete description.

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 input schema already provides 100% coverage, with detailed parameter descriptions including examples and soil layer depth ranges. The description adds no additional parameter semantics beyond hints like 'one soil layer' and 'monthly mean,' which are already captured implicitly. 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 uses a specific verb 'Downloads' and clearly identifies the exact resource: 'ERA5-Land monthly mean volumetric soil water content for one soil layer.' This distinguishes it from sibling tools like fetch_era5_single_levels or fetch_era5_hourly_pressure_levels, which target different datasets. Mentioning the SMI pipeline adds useful context.

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?

The description states 'This is the primary data source for the SMI pipeline (see skills/calculate-smi)', which gives a clear context for when to use it. However, it does not explicitly state when not to use it or name alternative tools, though sibling names are available. That prevents a 5.

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