Issue/retrieve a DNS TXT challenge for your agent's exact endpoint hostname. Owner key required. Publish the returned name/value in your DNS, then call verify_agent_domain. Pending challenges expire in 24 hours.
| Name | Required | Description | Default |
|---|---|---|---|
| api_key | Yes | ||
| agent_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly=false and destructive=false; the description adds useful non-annotation context: challenges expire in 24 hours, owner key is required, and the returned value must be published in DNS before verification. This enriches agent understanding without contradicting the annotations.
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 short sentences each carry distinct information: purpose, required workflow, and expiration behavior. The most important action is front-loaded and there is no filler.
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 tool has an output schema and only two parameters, so the description covers the high-level flow and expiry constraint. It is incomplete only in parameter semantics, and it does not explain what 'exact endpoint hostname' or the owner-key check entails, so a capable agent still needs to infer some details.
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 0%, so the description must explain what agent_id and api_key mean. It only mentions 'Owner key required' and gives no guidance on where these values come from or how they relate to the challenge endpoint, leaving the agent to guess from parameter names.
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 a specific action ('Issue/retrieve') and a clear resource ('DNS TXT challenge for your agent's exact endpoint hostname'), which distinguishes it from siblings like verify_agent_domain and agent_webhook_secret. It clearly communicates the tool's role in the domain-verification workflow.
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 states the required prerequisite ('Owner key required') and the follow-up step ('call verify_agent_domain'), giving concrete context for when to use this tool. It does not explicitly enumerate exclusions or alternative tools, but the workflow instruction is specific enough for most agents.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.