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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read nature is covered. The description adds that the catalogue is free and limited to product/shared-service information, which is useful context. It does not contradict the annotations and provides a modest amount of additional behavioral scope.

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 short sentences with no filler. The key identifier, 'capability and MCP tool catalogue for Rates by 402rates', is front-loaded, and the scope qualifier is a necessary clarification. Every word 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 zero-parameter, read-only catalogue tool with annotations covering safety and open-world hints, the description is sufficient. It defines the resource, the scope, and the product context. It could mention what a returned catalogue contains, but the absence of an output schema and the simplicity of the tool keep the gap minor.

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 no parameters, so the description does not need to explain parameter semantics. The empty schema fully covers the input surface, and the description's claims about containing product/shared service information are consistent with a zero-parameter catalogue tool.

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 identifies the tool as a 'capability and MCP tool catalogue' for 'Rates by 402rates', which makes the resource and scope clear. It lacks a strong verb, but the title's 'List' plus the catalogue wording convey the purpose. The phrase 'Contains this product and shared service information only' helps distinguish it from feature-specific tools.

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 implies this is the entry point for discovering available tools and capabilities. It does not explicitly state when to use it versus sibling tools or provide exclusions. The 'this product and shared service information only' qualifier gives some scope guidance but no direct routing.

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