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

Annotations already declare readOnly, idempotent, non-destructive behavior, and the description adds return semantics: today's USD market price, 30-day percent change, sorted most-expensive-first. It does not cover pagination or what happens with non-matching games, but the added output behavior goes meaningfully beyond the annotation set.

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 sentences, zero filler, and the intent trigger is front-loaded before the return-format and alternative-tool guidance.

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?

Output schema exists so return values need not be spelled out further; annotations cover the safety profile; the description supplies the selection trigger, the alternative tool, and the sort/return shape. Nothing an agent needs to invoke this correctly 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% and both parameters (game enum, limit range) are fully documented in the schema, so the description correctly does not duplicate them. It adds no syntax or defaulting nuance beyond the structured data, so 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+resource ('sealed product prices in one game') and enumerates the covered product types (booster boxes, ETBs, bundles, packs, tins, cases), which cleanly separates it from siblings like set_prices or card_price.

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?

Explicit trigger ('when the user asks about sealed product prices in one game') plus an explicit alternative for the adjacent case: 'For one named product, search_cards plus card_price is more direct.' Both when-to-use and when-to-use-something-else are covered.

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