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

With no annotations, the description carries the full behavioral burden, and it delivers: it discloses the one-time signing secret, that it is never shown again, and the exact permission scope ('that path and everything beneath it, nothing above'). This is essential operational context the schema could never express.

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 sentences, each earning its place: the action, the critical secret warning, and the permission boundary. No filler, no repetition of schema details, and the most important operational warning 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?

For a one-parameter tool with no output schema and no annotations, the description covers purpose, return artifacts (challenge + signing secret), required user action (store the secret), and the permission scope. It does not explain the verification flow, but that belongs to verify_destination and is not needed to call this tool 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?

The schema already documents the url parameter at 100% coverage, giving a baseline of 3. The description adds meaningful path-scope semantics — 'covers that path and everything beneath it, nothing above' — which clarifies how the single parameter is interpreted beyond the schema text.

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 says 'Claim an https:// URL you control,' which combined with the title makes clear this registers a delivery destination. It adds context about the challenge/secret response and the path-scoped permission, but it does not explicitly distinguish itself from siblings like verify_destination or delete_destination.

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 gives clear context: use this when you control an https URL and want to claim it as a destination. It also provides a sequencing rule — store the one-time signing secret before doing anything else — but it does not explicitly state when not to use it or mention the intended verify_destination follow-up.

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