About the Sponsor Registers

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

The readOnlyHint annotation already indicates a safe read operation. The description adds value by specifying the scope (statistics, freshness, terminology) and the UK/Netherlands geographic focus. It does not introduce any behavioral contradictions or unexpected side effects.

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?

Two sentences, with the core function front-loaded and a practical usage example. Every word earns its place, and there is no redundant repetition of the tool name or schema.

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 zero-parameter, read-only informational tool, the description provides adequate context about what the tool returns and when to use it. While there is no output schema, the description names the key content areas, making the return structure predictable enough for an agent.

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?

The tool has 0 parameters, so parameter descriptions are unnecessary. The baseline of 4 applies because there is nothing to explain; the description's focus on content is appropriate.

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 provides register statistics, data freshness, and terminology for UK and Netherlands sponsor registers. It also gives a concrete use case ('explain what a licence, route, rating, or sponsor type means'), which distinguishes it from sibling tools focused on checking licenses or searching for sponsors.

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 includes a direct usage instruction ('Use this to explain...'), which gives a clear context for when to invoke this tool. While it does not explicitly mention alternatives or exclusions, the context is strong enough to guide selection among siblings.

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