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

Annotations already cover read-only/idempotent/destructive, and the description adds substantial behavior beyond them: prices are 'observations ... not guarantees'; withheld listings are marked withheld_by_channel_policy; links are user_navigation handoffs not for automatic clicking; canonical_page carries the complete table. No contradiction.

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 long but dense and front-loaded with the core return statement; each clause adds real semantic detail needed because there is no output schema. It sacrifices readability by packing many fields into a single prose block, so it's not a 5.

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?

Given the absent output schema, the description covers the main return fields, the optional lowest_observed shape, source withholding semantics, and link usage, which is enough for an agent to invoke the tool and interpret results. Minor omissions like condition semantics don't materially undercut completeness.

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?

With 0% schema description coverage, the description compensates by clarifying that product_id accepts a slug or edition_id and stating the region default/provenance. The optional condition parameter, however, is left entirely to the enum, so not all parameters receive the same treatment.

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 precise verb+resource: 'Returns the current merchant offers of one product' and enumerates identifying inputs. The scope (one product) and read-only nature distinguish it from dealing/search/compare siblings, even without naming them.

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 clear context for when it applies (current offers for a specific product; read-only, no purchase execution) and even warns that returned links are navigation handoffs not for prefetching. It does not explicitly name sibling alternatives or state when not to use it, so it stops short of a 5.

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