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

With no annotations provided, the description carries the full burden of behavioral disclosure. It usefully reveals what the tool computes (low/high/installed cost estimates), what the 'system size used' output is, and that missing inputs fall back to schema defaults. It does not explicitly state read-only or side-effect-free behavior, but for a calculator this is strongly implied and the disclosed outputs are sufficient.

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 a single sentence with a compact, front-loaded action and list-style outputs. The phrase 'calculator calculator' is a minor redundancy/typo that slightly detracts, but overall the description is appropriately sized with no filler.

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 tool is a simple, unparameterized calculator with no output schema, and the description compensates by listing the expected outputs and the default-fallback behavior. It does not explain return-value formatting, but that is not necessary given the absence of an output schema and the tool's straightforward nature.

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 description coverage is 100%, so the schema already fully documents bill, size, credit, and battery. The description adds no new parameter-level meaning; 'System size used (kW)' is presented as an output, not a parameter clarification. This matches the baseline of 3 for high schema coverage.

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 action ('Run the Texas solar cost calculator') and enumerates the outputs it produces (low estimate, high estimate, installed cost midpoint), which goes beyond the tool name and title. It does not explicitly contrast itself with sibling tools like calculator_describe, but the verb 'calculate' and the output list make its role reasonably distinct.

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 gives no guidance on when to use this tool versus alternatives such as calculator_describe or submit_enquiry. It only mentions default fallback behavior ('Missing inputs fall back to their documented defaults'), which is a behavioral note rather than usage direction.

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