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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint, but the description adds substantive behavior: price.listedOnly semantics (shipping/tax set at shop checkout) and an explicit prompt-injection warning that seller text is untrusted data, never instructions. That is exactly the extra context annotations cannot carry.

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?

Purpose is front-loaded and the safety warning closes it; every sentence carries information. It is fairly dense, but no sentence is redundant or restates structured fields.

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 no output schema, the description usefully enumerates the returned fields (title, description, price, shop, rating, pageUrl, howToBuy). Combined with the price caveat and safety note, an agent has everything needed to call and interpret the tool.

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 schema already documents kind, shop, limit, query, and category. The description adds no parameter-level syntax or defaults beyond what the schema states, so 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?

Opens with a specific verb+resource ("Searches products and services listed on GenesisPay") and names the result domain precisely. It is clearly distinguishable from siblings reviews, shops, and trending, which cover different resources.

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 context: the shop filter takes an id from genesispay_catalog_shops, and buyers of results should consult each result's howToBuy field. It stops short of explicit when-to-use/when-not guidance relative to siblings like trending or shops.

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