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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered. The description adds the returned field list but says nothing about pagination, result size, or the free-vs-PRO tier behavior implied by the _atom_api_key parameter.

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?

Two short sentences, zero redundancy, with the core scope front-loaded and the filter capability second. Every clause earns its place.

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 names the returned fields and the free/PRO tier distinction is documented in the schema. It is nearly complete, lacking only scale/pagination behavior for a fleet-wide listing.

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 baseline is 3. The description restates the channel/region/country filters but adds no syntax, accepted values, or matching behavior beyond what the schema already documents (including channel codes DEV/CLD/PLT/NCL).

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 states a specific verb (list) and resource (every vendor in the Attic Standard fleet) and enumerates the returned attributes (channel, country, region, pricing page). It does not distinguish itself from the nearby sibling get_vendor_catalog, which sounds like it could overlap, so it falls short of 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?

It says 'Filter by channel, region or country,' which implies the intended use of the filters, but gives no explicit when-to-use guidance, no exclusions, and does not route the agent to an alternative tool for deeper vendor data.

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