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

No annotations are provided, so the description bears the full burden. It discloses a prerequisite and the return value ('Returns the created domain summary'), but does not mention verification behavior, duplicate handling, or permission requirements. This adds useful context but is not exhaustive for a create operation.

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 sentences, each earning its place: purpose, prerequisite/guidance, return, and cost. It is front-loaded and concise with no fluff.

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?

The description covers all essentials for a moderate-complexity tool: what it does, the prerequisite, how to handle connection targeting, and what it returns. With full schema coverage and an existing output schema, no significant information gaps remain.

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 baseline is 3. The description adds valuable meaning for clerk_instance_id ('Pass to target a specific connection, or omit to use the default account'), going beyond the schema's explanation. This enrichment justifies a 4.

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 opens with 'Add a domain to a Clerk organization,' a specific verb+resource that clearly defines the operation. It distinguishes itself from sibling tools like update/delete/list organization domains by using 'add' and specifying the resource.

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 a concrete prerequisite ('Call clerk.get_connected_accounts first') and clear guidance on targeting connections via clerk_instance_id or using the default account. While it lacks explicit exclusions or alternative tool mentions, it gives strong contextual instructions for when and how to use this tool.

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