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

The annotations already declare read-only, idempotent, non-destructive, and closed-world behavior, so the bar is lower. The description adds valuable content beyond that by enumerating exactly what is compared (mechanism, generation, trial weight loss, maintenance dose, prices in CAD), which helps the agent understand the output without an output schema.

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: the first front-loads the comparison scope and fields, and the second gives the usage trigger. It is tight and every element 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 comparison tool with no output schema, the description provides enough detail about what will be compared and when to use it. No additional behavioral or parameter information is needed 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 tool has zero parameters, so no parameter semantics need to be documented. Per the rubric, zero parameters yields a baseline score of 4.

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 (side-by-side comparison) and resource (the three GLP weight-loss medications Deer Supply sells), naming each medication and the compared attributes. It is clearly distinguishable from siblings like search_products or get_product, which handle individual products.

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 says to use this when someone is choosing a weight-loss option, giving clear context. It does not name alternatives or state when not to use it, so it falls short of the highest level.

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