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

With no annotations provided, the description carries the burden. It discloses the return shape ('custom domain summaries and total_count') and the cost (5 tokens), but does not detail pagination, ordering, or any side effects. This is adequate for a read-only list operation but not rich.

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?

Four concise sentences, each with a clear purpose: what it does, prerequisite/parameter usage, return values, and cost. No fluff, well front-loaded with the primary action.

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 tool with one parameter and an output schema, the description covers purpose, prerequisite, parameter semantics, return values, and even cost. It is complete for the tool's complexity; no missing critical context.

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 clerk_instance_id. The description mostly restates the schema ('Pass clerk_instance_id to target... or omit it'), adding minimal extra meaning beyond the prerequisite connection. Baseline 3 is appropriate.

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 clearly states the action: 'List custom domains configured for a connected Clerk instance.' This is a specific verb+resource that distinguishes it from other list_* tools, such as list_organization_domains, by focusing on custom domains for a connected Clerk instance.

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?

Provides explicit usage guidance: 'Call clerk.get_connected_accounts first' and explains the clerk_instance_id parameter behavior (pass to target specific, omit for default). This is clear context with a prerequisite, though it does not mention when not to use it or alternatives.

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