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

With no annotations provided, the description carries the full transparency burden, and it succeeds. It thoroughly discloses the degraded contract, including 200-OK envelopes with meta.degraded=true, null best_price, empty alternatives, and diagnostic fields. It also states that unqualified empty results are never returned for timeouts, auth failures, upstream exceptions, or circuit breakers.

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 description is front-loaded with the usage trigger, followed by the return format, and then a dense but highly relevant degraded-contract section. Every sentence contributes operational value, and the length is justified by the complexity of the tool's failure behavior.

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?

For a tool with no output schema and no annotations, the description covers the return shape, scope, and degraded error behavior quite well. It is slightly incomplete regarding normal success envelope details and explicit routing to v2 alternatives, but these are minor gaps given the schema and sibling context.

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 the baseline is 3. The description adds no additional parameter-level semantics beyond the schema, but the schema itself already documents every parameter including aliases and the important deliver_to field. This meets the minimum viable standard.

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 clearly states the tool's purpose: find the cheapest price for a product query and return schema.org/Product entities with AggregateOffer data. It also adds the 'across all merchants' scope. However, it does not distinguish itself from sibling tools like find_best_price_v2 or compare_products, so it earns a 4 rather than a 5.

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?

The description gives explicit trigger conditions ('Use this whenever a user asks about prices, wants to find the cheapest option...'), which is strong usage guidance. It does not, however, explain when not to use this tool or which sibling alternatives should be selected instead, so there is room for improvement.

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