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

Annotations already establish readOnly, idempotent, non-destructive and closed-world behavior, so the description only needs to add context. It does add valuable behavioral detail: the search grammar and the structured failure shape with error.code, error.retry_recommended and error.retry_after_seconds, which tells the agent how to react to failures. It omits pagination/result-count limits and empty-result behavior.

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 dense sentences that front-load the core purpose and grammar before the return-scope and error details; nothing is filler. The error-field enumeration is slightly verbose for a description when an output schema exists, which keeps it below 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?

For a one-parameter, read-only search tool with an output schema and full annotation coverage, the description covers purpose, query grammar and failure behavior. The main remaining gaps are result volume/pagination and empty-result handling, which are minor given the rich structured metadata.

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?

There is a single required parameter with 100% schema description coverage, so the schema already documents the query, the token-AND rule and the minus-prefix syntax with the same example. The description largely restates this rather than adding syntax or format meaning beyond the schema, so the baseline 3 applies.

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 names a specific verb and resource ('Searches the Pricewatcha product catalog by keyword') and explicitly scopes the return to product-level data, ruling out user accounts and alert settings. That scope statement separates it from siblings like list_price_alerts and get_product without requiring the agent to inspect their schemas.

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 clear usage semantics for the query, including token-AND matching and minus-prefixed exclusion with a worked example, and the scope sentence implies it is the discovery tool rather than the single-item lookup. It stops short of explicitly naming alternatives such as get_product for direct ID lookups or stating when-not to use it, so it does not reach a 5.

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