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

readOnlyHint covers the safety profile, and the description adds that the tool is free and returns a description rather than sample output. However, it does not explain what 'Free' means or characterize the returned fields beyond a short list, so behavioral detail remains thin.

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 redundant schema repetition, and the alternative call is placed at the end. The leading sentence fragment 'Free.' is terse but not wasteful; minor structural polish would make it a 5.

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 info tool, the description covers what the agent gets (price, network, return description) and where to go for a sample, which is sufficient to invoke correctly. It stops short of enumerating the output format, but try_it_free covers that need.

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 input schema has zero parameters, so there is no parameter meaning to document; the baseline of 4 applies. The description does not need to compensate for any parameter documentation gap.

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 the tool surfaces service-level information ('Price, network, and what this service returns') and distinguishes itself from try_it_free by offering a description rather than a sample. It is clear enough, though it leans on the tool name for the verb and leaves the leading 'Free.' slightly ambiguous.

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?

Explicitly routes to try_it_free when the agent needs an actual output sample rather than a description, which is a clear use-vs-alternative condition. It does not discuss compare_products or get_product_details, but their names make the boundary less critical.

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