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

Annotations already cover safety (readOnlyHint, destructiveHint=false, idempotentHint, openWorldHint), so the bar is lower. The description adds real value by disclosing what comes back ('Worth tracking links') and a hard behavioral rule not to fabricate retailer URLs, which an agent would otherwise likely do.

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 short sentences, front-loaded with the when-to-use trigger followed by what it returns and the anti-hallucination rule. Every sentence earns its place with no filler.

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?

An output schema exists, so return values need not be re-explained, and annotations cover the safety profile. The description supplies the trigger condition and the critical URL-fabrication constraint, though it omits any mention of result quantity, ranking, or geographic scope for the `place` parameter.

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 all four parameters (place, title, intent, category) are already documented in the schema. The description's mention of buy new/buy used/sell loosely maps to the intent enum but adds no syntax, format, or constraint detail beyond the schema, making the baseline 3 correct.

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 states a specific verb+resource: it returns a store or marketplace link for buying new, buying used, or selling. This is clearly distinct from price-oriented siblings like compare_prices and price_item, though the description never names those siblings explicitly to sharpen the distinction.

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?

'Use when the user wants a store or a marketplace link to buy new, buy used, or sell' gives a clear triggering condition, and 'Do not invent retailer URLs; use only the links in the result' is a concrete usage constraint. It does not state when to prefer this over compare_prices or price_item, so it stops short of full alternative routing.

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