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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely non-obvious context beyond the annotations: the data comes from "the latest crawl" and therefore is snapshot/stale rather than live, and it enumerates the profile contents (traffic estimates, competitors, pixels) that would otherwise be hidden without an output schema.

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?

A single front-loaded sentence with no filler, opening with the core purpose before enumerating payload fields. The long field list is dense but earns its place because no output schema exists to document the return shape.

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 one-parameter read-only lookup with no output schema, the description covers purpose, data provenance, and return contents adequately. Remaining gaps, such as behavior for an unknown domain and the implicit contrast with find_stores, are minor but real.

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% for the single domain parameter, including an example format (gymshark.com), so the schema carries the parameter burden. The description adds no additional syntax, normalization, or error semantics for the domain, which is the baseline-3 case.

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-equivalent (look up) and resource (one Shopify store's profile), and enumerates the returned fields, so the agent knows exactly what comes back. It does not differentiate itself from siblings like find_stores or technology_usage, which is the only thing keeping it from a 5.

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 phrase "One Shopify store's profile" implies a single-store lookup as opposed to the plural find_stores search, which is weak implicit routing guidance. There is no explicit when-to-use, when-not-to-use, or named alternative, so the agent must infer the split from the sibling names.

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