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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true. The description adds genuinely new behavior: it never adds to cart, orders, or pays, and results are cached for one hour. That caching/rate characteristic is valuable and not present in structured fields, though it says nothing about failure modes or how the checks are reported.

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 in the first clause, followed by the checks, the read-only guarantee, caching, and the 'Use when' trigger. The long enumeration of checks is dense but each item is meaningful. Sentence count is low and nothing is 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?

There is no output schema, so the description carries the burden of explaining what comes back. It lists what is inspected but never describes the result shape (a verdict, score, or per-check findings), leaving the agent to guess how to interpret the response. It is adequate but has a clear gap for a no-output-schema 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 coverage is 100%, so both parameters (domain, customer_request) are fully documented in the schema, including an example and the optional plain-language use case. The description's JSON example restates the required domain parameter rather than adding semantics. Baseline 3 is warranted when the schema does the heavy lifting.

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 and resource ('Checks a store') and enumerates exactly what is examined: anti-bot walls, robots.txt for shopping agents, UCP profile/checkout, storefront MCP, structured data, and a price/stock truth check. An agent immediately knows the tool's scope. It does not, however, differentiate itself from siblings like check_reliability or find_shop, which an agent must distinguish on its own.

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 an explicit 'Use when' trigger: before buying from a store, or to know whether its prices can be trusted. That is clear deployment context. It stops short of naming alternatives or when NOT to use it (e.g., vs. check_reliability or find_shop), so no exclusions are provided.

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