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

Annotations already establish readOnly, idempotent, and non-destructive hints, so the description adds value by explaining exact query behavior: token AND, irrelevant word order, and minus-prefixed exclusions. It also documents the exact failure response shape, which is useful operational behavior not captured by the annotations.

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 three sentences, all of which are informative and non-redundant. The primary action is front-loaded, key query semantics are compactly explained, and the error object detail is concrete without padding.

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?

With only one input parameter, full schema coverage, output schema presence, and safety/caching hints already provided by annotations, the description fills the remaining gaps: search semantics, scope of results, and structured failure mode. Nothing essential is missing for an agent to select and invoke this tool correctly.

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?

The schema already covers the query parameter 100%, so the description is not strictly required to add parameter info. It does add meaningful behavior beyond the schema by explaining word order, AND semantics, and exclude-term syntax, which helps the agent formulate a properly structured query.

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 opens with a specific verb and resource: 'Searches the Pricewatcha product catalog by keyword.' It also distinguishes this tool from siblings by clarifying that it returns product-level data only, not user accounts or alert settings, and explains the query semantics. This is a clear and non-tautological statement of what the tool does.

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 makes clear it is for keyword-based product catalog search and explicitly excludes user accounts and alert settings, giving a when-not-to-use signal. However, it does not explicitly name alternative sibling tools (e.g., use get_product for a direct product lookup), so the guidance is helpful but not fully exhaustive.

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