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

Annotations only indicate readOnlyHint=true; the description adds significant context: the score range, data source (BLS PPI), z-scoring methodology, historical depth to 1973, daily updates, and the exact return fields. This goes well beyond what annotations provide, making the tool's behavior highly transparent.

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 three sentences with no fluff: the first delivers the core functionality and formula, the second gives precise usage triggers, and the third reports update frequency. Every sentence earns its place, and the most critical information is front-loaded.

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 covers output fields, methodology, historical depth, and use cases, and the schema details the optional parameter. It does not explicitly explain how to interpret the score (e.g., what constitutes 'high stress'), but the 0-100 range and the title imply a monotonic interpretation, so the gap is minor.

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 single optional parameter 'days' is fully described in the schema (purpose, range, tier requirement, and fallback behavior). The main description adds no parameter-specific details beyond what the schema already covers, 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 clearly states it returns a 0-100 soil-input stress score with a specific formula (z-scored year-over-year BLS fertilizer/ag-chemical PPI changes) and lists the output fields. This verb+resource+scope is highly specific and distinguishes the tool from siblings, even without their descriptions.

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 explicitly enumerates when to call: user queries about fertilizer prices, input cost inflation, agricultural input stress, and timing fertilizer procurement, prepay pricing, or farm-budget decisions. However, it does not mention when NOT to use it or name alternative tools, so it stops short of a full 5.

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