favourites

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the meaningful auth constraint ("Requires login") and the priced nature of the returned data, which is real value beyond structured fields. It stops short of confirming this is a side-effect-free read or describing scope/pagination, but the tool is a zero-parameter listing and an output schema exists, so the remaining gap is moderate.

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?

Two short sentences with no filler, and the resource statement is front-loaded ahead of the login prerequisite. Nothing here is redundant with the schema.

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 tool with an output schema and no annotations, the description supplies what is missing: the content returned (favourite products with prices) and the authentication requirement. Only the differentiation from sibling favourites tools (is_favourite, add_favourite, my_products) is left unaddressed.

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 takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description does not need to compensate for any schema coverage gap (coverage is 100%).

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?

"Your favourite products, priced" identifies the resource (favourite products) and implies a listing with price data, so the verb/resource pair is inferable. However, it never states the operation explicitly (list/retrieve) and gives no differentiation from close siblings like my_products, is_favourite, add_favourite, or remove_favourite, leaving an agent to guess which of these surfaces the favourites collection.

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?

"Requires login" is a prerequisite, not usage guidance. There is no statement of when to choose this over my_products or is_favourite, and no exclusions or context about what a logged-in caller should expect to get back versus the sibling tools.

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