council_tax_band_lookup

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

Annotations already convey readOnlyHint and idempotentHint, so the bar is lower. The description adds useful context that this wraps an external public GOV.UK service and is experimental, implying possible volatility, but it does not discuss errors, rate limits, or data freshness.

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?

One sentence with no filler; the experimental warning and jurisdiction are front-loaded. However, the brevity reflects under-description rather than efficient completeness.

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 12-optional-parameter lookup tool, the description is too thin. It does not indicate which parameters are meaningful, how they relate, or when this tool is appropriate, so the agent must rely on an under-described schema and the output schema.

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 only 8%, and the description contributes no parameter guidance. It never explains postcode, street, town, propertyName, billingAuthorityReference, courtCode, or how these parameters should be combined, so an agent cannot construct a valid lookup from the description.

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 clear action ('lookup'), resource ('Council Tax band'), geography ('England/Wales'), and source ('public GOV.UK service'). It is more specific than the bare name, but it does not explicitly differentiate itself from sibling council_tax_query.

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?

No guidance on when to use this tool versus council_tax_query or the other lookup tools. It mentions the service is experimental and public, but gives no prerequisites, exclusions, or example use cases.

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