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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds real behavioral context beyond them: free-text mentions of airline/size are auto-applied as filters, and regular_price_eur appears only for sale items. It doesn't discuss pagination or result limits, keeping it from a 5.

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-loaded with purpose, then examples, then behavior, then return fields. Slightly dense with brand and category enumeration, but every sentence carries usable information with little waste.

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 10-parameter, zero-required search tool with no output schema, the description covers catalogue scope, market behavior, auto-filtering, and the shape of returned fields (price, availability, dimensions, URL). Nothing essential to correct invocation is missing.

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 90%, so the schema already documents parameters well (baseline 3). The description adds value by explaining that free text may embed airline/size that get applied as filters automatically, and by describing the return fields, going beyond the schema.

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?

States a specific verb (search) and resource (in-stock luggage catalogue) with explicit scope: brands, product categories, and two markets. Clearly distinguishable from siblings like get_product (single item) and check_airline_fit (fit check).

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?

Gives concrete usage examples ('cabin suitcase for Ryanair under 80 €') and signals it is the entry point for shopping questions. It does not explicitly name alternatives such as get_product or check_airline_fit or state when NOT to use it, so it falls short of a 5.

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