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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, yet the description still adds real behavior: the response language is French, the tie case returns tied: true with no elected winner, and the required two-call pattern. It discloses more than the annotations alone could convey.

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 call sequence is front-loaded, followed by output obligations, the read-only note, language constraint, and the tie edge case. Every sentence carries a distinct instruction and none is redundant.

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?

There is no output schema, so the description carries the burden and does: it describes the verdict, the productUrl field, the tied flag, and the language of the payload. Nothing an agent needs to call or correctly present results is missing.

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%, so the baseline is 3, but the description goes further by explaining that answers must be gathered from the no-answers call and that budget is supplied on the second call, giving the parameters workflow meaning the schema cannot express on its own.

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?

States a specific verb and resource — returns the Pryx verdict (which product to buy) for one category — and pins down the precondition (questions answered). An agent can distinguish this from pryx_categories (slug source) and pryx_product (single-product detail) without opening any schema.

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?

Gives an explicit two-phase protocol: call WITHOUT answers to fetch the questions, then call again with budget and answers. It also prescribes downstream behavior (always show productUrl, never present a winner when tied: true), which is unusually complete routing guidance.

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