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

Annotations already declare this as read-only, idempotent, and non-destructive, so the description does not need to repeat that. It adds useful context about the scope of information, but does not describe any additional behavioral traits such as response format, latency, or content variability beyond what the output schema likely covers.

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 two sentences with no wasted words. It front-loads the core purpose, then lists supported topics, and ends with clear exclusions, making it easy for an agent to parse and act on.

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 information tool with a rich output schema and clear annotations, this description covers what the tool offers and what it does not. The explicit topic list and exclusions leave little ambiguity about when this tool is the right choice.

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 zero parameters, and the schema coverage is 100%, so there are no parameter semantics for the description to add. The description appropriately focuses on the tool's information scope rather than parameters.

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 identifies the tool as providing product information for England Works Watch, with a detailed list of covered topics. It explicitly distinguishes itself from sibling tools by stating what it is not for, such as supported-event lists and change decisions.

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 explicit 'Use for' guidance covering service scope, pricing, payment, MCP endpoint, and legal disclaimer topics. It also provides explicit 'Not for' exclusions that map to sibling tools like list_supported_change_events and assess_change_impact, making alternative selection straightforward.

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