si_api_register

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

With no annotations, the description carries the full burden and does flag the two most important traits: this immediately commits a purchase and requires an API key. It stops short of cost, irreversibility/refund behavior, or what happens if the domain is unavailable, which matters for a financial mutation.

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?

One tight sentence that front-loads the mechanism and the purchase consequence. No filler; the parenthetical is the only extra and it carries real setup information.

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 2-parameter tool with no output schema, the description covers the essentials an agent needs: what it does, that it spends money immediately, and the auth prerequisite. A note on prerequisites like confirming availability first would make it fully complete.

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% and both parameters are documented there (including the example 'kinging.si' and the 1-year default). The description adds no parameter-level meaning beyond the schema, so the baseline 3 applies.

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?

States a specific verb (register/purchase) and resource (domain) plus the mechanism (Dynadot API, headless). 'Purchases directly without opening a browser' cleanly separates it from sibling check tools like si_check_domain and si_batch_check.

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 discloses the prerequisite (DYNADOT_API_KEY in .env) and implies the headless-vs-browser distinction, but never states when to prefer this over siblings such as si_fast_checkout, nor whether availability must be verified first. Usage is only implied.

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