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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose the return format (schema.org/Product with Offer properties) and the covered markets, and 'Get' implicitly indicates a read operation. However, it does not explicitly state that the operation is non-destructive, nor mention sorting direction (ascending/descending) for discount percentage, pagination behavior, or how invalid/missing deliver_to is handled. This is adequate but not thorough.

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 reasonably sized but contains redundancy: 'REQUIRED deliver_to' and 'Always pass deliver_to="SG"' convey the same message twice. The list of supported countries appears twice in slightly different forms (first as prose, then in the filter enumeration). It is front-loaded with the required parameter and purpose, but the redundant phrasing weakens overall conciseness.

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 9 parameters, no output schema, and no annotations, the description provides a decent overview but leaves gaps. It explains return type and filters, but does not clarify the relationship between region and country, the exact sorting order, or how pagination (limit/offset) behaves. The inconsistency about Indonesia vs. the enum also adds ambiguity. It is sufficient for basic invocation but not fully comprehensive for all edge cases.

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 a bit of guidance on deliver_to ('Always pass deliver_to="SG"...'), and it restates the filter dimensions (currency, region, country, category) but does not deepen understanding beyond the schema. The mention of coverage includes Indonesia, which is not present in the country_code enum, creating slight ambiguity rather than clarifying parameter semantics.

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 function: 'Get discounted products sorted by discount percentage.' It identifies a specific verb and resource, and adds scope by listing covered regions. However, it does not explicitly differentiate itself from the sibling tool 'get_deals' (v1), relying on the version suffix rather than naming what makes v2 distinct.

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 only usage guidance is 'Always pass deliver_to="SG" (or your buyer's country),' which is really a parameter requirement rather than guidance on when to choose this tool over alternatives. It does not mention any when-not-to-use conditions, exclusions, or compared search_products, get_product, or find_best_price. The coverage list gives some context but no routing between siblings.

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