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

With no annotations, the description carries the behavioral disclosure burden. It discloses that the tool returns charge points, cable routes, minimum power, and cost caps/exemptions, and it flags 'Indicative' as a limitation. It does not explain the underlying methodology, but the output behavior is clearly stated.

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 compact sentences with no redundant wording. It front-loads the purpose and scope, then lists outputs and the 'Indicative' caveat. 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?

For a 5-parameter calculator with no output schema, the description names the key outputs and applicability scope. It does not explicitly state input dependencies like 'dwellings for residential' or 'covered_car_park for non-residential', but these are partly inferable from the schema descriptions. Overall, this is reasonably complete for correct invocation.

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 60%, so the description needs to add some parameter-level meaning. It adds useful domain context like the 1-in-5 cable route rule for non-residential, but it does not clarify parameter dependencies such as when dwellings or covered_car_park should be provided. The schema covers some fields, but the gap for the remaining parameters is not fully compensated.

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 names the exact regulation (UK Approved Document S 2021), the resource (EV charge-point requirements), and the applicable scope (new build/major renovation, residential/non-residential). This clearly differentiates it from sibling tools like part_o_overheating or uk_planning_checker.

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 clear applicability for new build and major renovation in residential and non-residential settings. It does not explicitly list exclusions or alternatives, but the scope is specific enough for an agent to know when to select this tool.

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