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

With no annotations, the description carries full burden but only states inputs and outputs. It fails to disclose the calculation model (e.g., discount rate, inflation assumptions), potential limitations, or whether it is read-only. This leaves the agent unaware of 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?

The description is very concise with five short sentences, each adding value. Purpose is front-loaded, and every sentence earns its place without fluff or redundancy.

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 the existence of an output schema, the description adequately covers basic function and inputs/outputs. However, it lacks depth on calculation assumptions (e.g., constant electricity price, no discount rate) and does not differentiate from related sibling tools, leaving gaps in completeness.

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?

Although schema descriptions cover 100% of parameters, the tool description lists inputs as 'install cost, kW capacity, location production, kWh price,' which do not exactly match the schema parameter names (system_cost, annual_kwh, price_kwh) and units. This discrepancy could mislead the agent about required data.

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 the tool computes solar panel ROI over its lifetime, using a specific verb and resource. However, it does not explicitly distinguish itself from sibling tools like calculate_solar_panel_output, which could lead to confusion.

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 suggests use for energy audits and points to list_bundles for related calculators. However, it lacks explicit guidance on when not to use this tool versus alternatives, and does not mention prerequisites or exclusions.

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