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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds non-obvious behavioral context: filters can be combined, a keyword is optional, and on-sale products expose a 'was' price. This goes beyond the structured annotations and helps the agent know what to expect from the response.

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 with no filler. It front-loads the core action, then return contents, then advanced usage. Every sentence adds necessary information, and the no-keyword caveat is placed at the end where it's digestible.

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 an 8-parameter search tool with a full schema, safety annotations, and an output schema, this description covers scope, return fields, and filter behavior. Pagination is handled through schema descriptions for offset and next_offset, so the description doesn't need to repeat it. The tool is well-specified for autonomous invocation.

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 coverage is 100%, so the baseline is 3. The description adds semantic value with explicit examples of filter combinations and the no-keyword case, which clarifies how parameters interact (e.g., on_sale=true alone; price_max with in_stock_only=true). It doesn't redefine each parameter, but it supplements the schema with usage patterns.

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 'Search this store's products by keyword and/or filters,' naming the exact action and resource. This distinguishes it from siblings like list_products (browse all) and get_product (single product) by emphasizing keyword/filter-based retrieval, and it scopes to 'this store's products,' setting it apart from a generic search sibling.

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?

It provides concrete usage context, stating that filters can be combined and used without a keyword, with examples like on_sale=true alone or price_max with in_stock_only=true. It does not explicitly name alternatives or when-not-to-use, so an agent might not know to use list_products for unfiltered browsing or get_product for item-level details, but the usage conditions are clear.

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