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

With no annotations, the description carries the full burden and does well: it discloses the data source (Power to Choose), cost boundaries (incl. delivery, excl. taxes), the estimate/non-offer caveat, and licensing constraints (free non-commercial with attribution, Pro for commercial). It omits return format and whether results are ranked or paginated.

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?

Three dense sentences, front-loaded with the core definition and immediately followed by the estimate caveat and licensing terms. Every clause carries information, though the licensing sentence could arguably be split for readability.

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?

For a 6-param tool with no annotations and no output schema, the description covers the caveats an agent most needs (estimate, data date, EFL disclaimer, licensing). It implies per-utility results via 'in each Texas utility' but does not describe the shape or size of the return, leaving a minor gap.

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 all six parameters are already documented in the schema; the baseline is 3. The description adds no parameter-level detail (kwh, months, EV fields) beyond what the schema states.

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?

States a precise verb+resource+scope: the fixed-rate plan with the lowest estimated annual cost, per Texas utility, for a given usage. An agent can grasp the output shape from 'in each Texas utility'. It stops short of naming how it differs from the close sibling electricity_rank_plans, so 4 rather than 5.

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?

Gives an explicit trigger ('Use for questions like "what is the cheapest electricity plan in Texas right now"') and an output-disclosure rule ('say it is an estimate as of the data date'). It offers no when-not conditions and does not route to alternatives such as electricity_compare_my_plan or electricity_rank_plans.

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