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

Annotations already cover read-only/idempotent safety, but the description adds substantial behavioral context beyond them: the ranking rule that US retailers and brand stores outrank China-marketplace offers, and that China offers only appear when at least 15% cheaper for the same model. It also discloses which fields come back (condition, is_marketplace, marketplace, ships_from, delivery_days_max, shipping_cost, seller_type, store_rating, best_coupon), which the annotations say nothing about.

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 purpose is front-loaded in the first sentence, which is good, but the text then becomes a long run-on that mixes 20 example brand names with output-field inventories. The brand enumeration and field lists are information-dense but largely filler for the tool-selection decision.

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 carries the burden of explaining return values, and it does so well (condition, marketplace labels, coupon object shape). Input semantics are less complete, but for a search tool with a single required parameter this is close to sufficient.

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 only 44% across 9 parameters, so the description should compensate for undocumented inputs. It explains the condition values and the marketplace/coupon semantics of results, but min_discount, max_price, retailer, and limit are never addressed, and ships_from/include_marketplace are only touched on indirectly.

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 names a specific verb and resource (search consumer-tech deals on MoneyDeals US) and scopes it by product name, model, brand or category. It clearly states what domain it covers and names list_brands as the place for the full brand list, though it never distinguishes itself from siblings like get_deal, compare_products, or price_history.

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?

It tells the agent to use list_brands for the full brand list and to mention condition/ships_from/delivery time when presenting results, which implies usage. However, there is no explicit when-to-use guidance against get_deal, compare_products, or price_history, so routing to alternatives is left to inference.

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