request_otp

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

With no annotations, the description carries the full burden. It states the primary action (sending an OTP) and its purpose (starting authentication). However, it does not disclose side effects, delivery characteristics, error possibilities, or whether any prerequisites exist. For a relatively simple send tool, the transparency is adequate but not detailed.

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 sentences, front-loaded with the action, and includes a practical usage tip. Every word earns its place; no fluff or repetition. It is a model of conciseness.

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 single-parameter tool with no output schema, the description covers the essential what and when. It does not mention return values or the next step (e.g., verifying the OTP), but these are inferable from sibling tools. Given the low complexity, the description is reasonably 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?

The schema already provides a full description of the parameter: '10-digit mobile number' (100% coverage). The description adds no additional semantic meaning beyond confirming the destination ('to a mobile number'). Given the high schema coverage, the baseline score of 3 is appropriate.

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 clearly states the tool's function: 'Send an OTP to a mobile number to start authentication.' It uses a specific verb ('send') and resource (mobile number), and the phrase 'start authentication' distinguishes it from sibling tools like verify_otp. The addition of 'Call this first' further clarifies its role.

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 provides a clear usage condition: 'Call this first if not logged in.' This gives both a precondition and sequencing. It does not explicitly name alternatives (e.g., verify_otp), but the context makes it evident that this tool precedes OTP verification. The guidance is functional though not exhaustive.

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