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

With no annotations, the description carries the burden and does disclose the key side effect (an SMS is sent to a real user) and the OTP/non-OTP boundary. It does not mention failure modes such as invalid or already-registered numbers, rate limiting, or whether the code expires — gaps for a tool that triggers external messaging.

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 doing distinct work (purpose, exclusion, next step), with the action and sequencing front-loaded. 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?

For a 3-parameter, no-output-schema tool, the definition covers purpose, exclusions, and the follow-up call, which is enough to invoke it correctly. It stops short of saying what a successful response provides (e.g., a reference or expiry) that the agent would need before calling verify_login_otp.

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 all three parameters are already well documented (phone format, country code, notification message). The description's instruction to ask the user for the phone first adds workflow framing but no parameter-level meaning beyond the schema, so 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 and resource ('Send ChowDeck login SMS') and ties it to the endpoint semantics ('validate phone → auth/login'). It also explicitly carves out scope ('Does not accept OTP'), which separates it from verify_login_otp among the siblings.

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?

Gives an explicit ordered workflow: ask the user for their phone first, then the SMS code, then call verify_login_otp. The alternative tool is named along with the condition that selects it.

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