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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it enumerates what each match contains (site_id, workspace, Search Console status) and discloses the duplicate-brand warning, which is unexpected non-obvious behavior for the agent.

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?

Three tight sentences with zero padding: scope first, then return contents, then the alternative. Every sentence carries load and the key selling point (one call, all workspaces) is front-loaded.

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 compensates by naming what is returned and the cross-workspace warning condition. For a single-parameter read tool, an agent has everything needed to select and invoke it correctly.

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?

Only one parameter with 100% schema description coverage, so the schema already documents format and accepted examples (navyaai.com vs full URL). The description restates 'for a domain' but adds no format or edge-case guidance beyond what the schema gives, making the baseline 3 correct.

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 (find) and resource (the brand for a domain) plus the distinguishing scope: across EVERY workspace you belong to in one call. This clearly differentiates it from single-workspace lookups like get_site/list_sites without requiring the agent to open either schema.

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 final sentence gives an explicit alternative and the condition that selects it: 'Use this instead of listing workspaces one by one.' It doesn't name the sibling tool (list_workspaces) or state when not to use it, so it stops short of a full 5.

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