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

The annotations already indicate this is a mutating, non-idempotent action. The description adds valuable behavioral context beyond those hints: registration does not contact the endpoint, delivery stays disabled, and the endpoint remains in pending-verification until further steps are taken.

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?

The description is two short sentences with no filler. The main action is front-loaded, and the second sentence adds meaningful behavioral constraints without redundancy.

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 moderate-complexity registration tool with no output schema, the description covers state and side-effect behavior but does not explain the return value, verification flow, or why pending-verification matters. This is adequate but leaves gaps an agent would need to resolve through sibling tool names or prior knowledge.

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 needed to compensate by explaining parameter roles or relationships. It does not mention endpointUrl, transport, protocolVersion, maxPerHour, or minSeverity at all, leaving the agent to infer semantics from names and schema constraints alone.

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 uses a specific verb ('Registers') and identifies a clear resource ('account-scoped endpoint') plus its initial state ('pending-verification'). It also distinguishes itself from sibling challenge/verification tools by noting that registration never contacts the endpoint and delivery is disabled.

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 description implies when to use the tool: to create an endpoint in pending-verification state before later verification. However, it never explicitly names alternatives like create_monitor_a2a_endpoint_challenge or verify_monitor_a2a_dns_txt_challenge, nor does it state when not 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.