Compare product pricing

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

Annotations already declare readOnlyHint=true, and the description adds useful context about comparing current pricing and the valid product count. It does not mention return format or any edge behavior (e.g., unknown slugs), but that is not a serious gap for a simple read-only comparison tool.

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 short sentences front-load the purpose, then provide a when-to-use trigger and parameter guidance. No filler or repeated schema information.

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?

With one parameter, strong schema coverage, a readOnly annotation, and a clear purpose, the description is sufficient for an agent to select and invoke the tool. It could add a brief note about the output format, but the 'prices in one view' phrase already implies the result.

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 coverage is 100% with a clear '2-5 product slugs' description, so the schema carries the parameter meaning. The description goes beyond the schema by telling the agent that slugs can be found with search_products, adding integration guidance.

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 uses a specific verb ('Compare'), resource ('current pricing plans'), and scope ('2 to 5 SaaS products side by side'), which clearly differentiates it from sibling tools like search_products or get_product. It also ties the tool to named-product 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?

It explicitly states when to call the tool: 'when the user is choosing between named products and wants their prices in one view.' It stops short of naming sibling alternatives or stating when not to use it, so it lacks the explicit exclusion guidance of a 5.

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