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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds value by specifying the output content (slug, accepted URL parameters, languages/currencies) and providing an example that shows how the 'group' filter changes the result. It does not overstate capabilities, and the safety profile is consistent with annotations.

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?

Three sentences with no filler: first sentence states the purpose and outputs, second gives direct usage guidance, third provides a concrete example. The most critical information (what it does, when to use it) is front-loaded, and 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 simple list tool with one optional parameter and an existing output schema, the description is complete. It tells the agent what the tool returns (slug, URL parameters, languages/currencies), when to call it (before build_calculator_link), and how filtering works via the example. No critical information is missing 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?

The schema already provides a comprehensive description of the 'group' parameter with enum values and defaults (100% coverage). The description adds an explicit example that maps 'history' to 'what if I had invested' tools, which deepens understanding beyond the schema. This incremental value justifies a score above the baseline.

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 states a specific verb ('List'), a specific resource ('every SmartMoney77 calculator'), and the exact attributes returned (slug, URL parameters, supported languages/currencies). It clearly distinguishes from siblings by focusing on enumeration rather than calculation or link building, and explicitly references build_calculator_link as the dependent tool.

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?

Directly instructs when to use the tool: 'Call this before build_calculator_link.' This gives a clear use case and implies it should not be used after building a link. The example with the 'group' parameter further clarifies how filtering affects the output, reinforcing appropriate usage.

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