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

Annotations already declare read-only and closed-world, so the safety profile is covered; the description goes well beyond it by disclosing the two-call protocol, that output is in French for the French market, and the tie semantics (tied: true, no winner elected) with an explicit instruction not to present a winner. That is behavioral context the structured fields do not carry.

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 dense sentences, front-loaded with the tool's output, then the invocation protocol, then the caveat. No filler, and the critical tied-behavior warning is stated last where it will be read before acting on a result.

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 no output schema, the description must carry return-value semantics, and it does: verdict, French product names/explanations, and the tied case. Combined with 100% schema coverage on inputs, an agent has everything needed to invoke and interpret correctly.

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 description coverage is 100%, so budget and answers formats are already documented in the schema. The description only restates that the second call takes budget and answers, adding no format or constraint detail beyond the schema; baseline 3 applies.

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) scoped to one category, and ties itself to the sibling by naming pryx_categories as the source of the category slug. An agent can distinguish it from the category-listing sibling without opening either 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 obtain the questions, then call again with budget and answers. It also states the precondition (questions must be answered before a verdict exists) and instructs what to do when the response is tied, which is when-not guidance an agent could not infer.

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