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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds real value beyond them: prices exclude tax, links may be paid, offers only appear when one product clearly matches, and 'Divux does not check out' explicitly rules out a transactional action. What's missing is any hint about result volume, ranking, or pagination given a default limit of 10.

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?

Front-loads the primary action and the offer fallback, then moves to modifiers and caveats. It is information-dense and telegraphic, with no filler, though the compressed multi-clause sentences take a second read.

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 17-parameter tool with no output schema and very low schema description coverage, the definition covers purpose, key filters, and commercial caveats, but leaves roughly half the parameters unexplained and says nothing about what a result actually contains (price fields, offer counts, availability). Adequate but with clear gaps.

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 only 18% schema coverage across 17 parameters, the description must carry most of the weight; it explains query/brand/model, category, energy_star, country, product_id, and price bounds implicitly, but leaves detail, limit, condition, most_efficient_only, and the risky in_stock_only vs include_out_of_stock pair undocumented in both schema and prose. Core routing parameters are covered, so it is partially compensating but not fully.

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?

Opens with a specific verb and resource plus the lookup keys ('Find US products by name, model, barcode or brand and category') and states the follow-on behavior (offers on a single clear match). The only fuzziness is the 'US products' framing, which the later 'country selects US, AU or NZ' sentence widens — a minor internal inconsistency, but an agent still knows exactly what this tool retrieves.

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?

'Applies to product searches, store prices and ENERGY STAR appliance certification' gives concrete use contexts, and 'Supply product_id for offers on a chosen product' tells the agent the two-step discovery-then-offers pattern. It does not name any alternative tool or state exclusions, so it stops short of explicit when-not guidance.

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