router_send_sms

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that 'force' bypasses the Network Guard safety check, which is important context beyond the tool name, but it does not explain the consequences of bypassing the guard, whether SMS delivery is external or billable, or any permission requirements.

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 definition is short and front-loaded with the core action, followed by a compact parameter list. Every sentence and argument note adds useful semantic content, with no redundant restatement of the schema.

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?

The output schema exists, so return-value documentation is not required, and all three parameters are explained. However, for an SMS-sending tool with no annotations, the definition omits important context about side effects, safety-check implications, and delivery behavior.

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 must define the parameters, and it does: 'to_phone' is the recipient phone number, 'message' is the text content, and 'force' bypasses the safety check. This compensates well for the schema's lack of property descriptions, though it does not specify phone-number format or message-length limits.

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 states a specific verb and resource: sending an SMS message through the router SIM card. It is clearly distinct from the sibling router_read_sms, though it does not explicitly name alternatives or clarify scope beyond the core action.

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?

There is no guidance on when to use this tool versus alternatives such as router_read_sms, nor are there prerequisites or conditions for sending. The description only implies usage from the verb 'Sends' and gives no exclusions or contextual triggers.

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