Update SMS configuration

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

Annotations indicate idempotentHint=true, destructiveHint=false. Description adds that only customer-owned fields are updatable, tniq-owned fields are rejected, and lists specific errors (INVALID_REQUEST, TN_NOT_OWNED). No contradiction with annotations.

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?

Two concise sentences. Front-loaded with update verb and resource. No fluff or repetition. Every word adds value.

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 5-parameter, non-destructive update with no output schema, the description covers constraints, errors, and alternative tool. Annotations provide safety profile. Complete enough for correct invocation.

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% for 5 parameters. Description adds context by naming the updatable fields and clarifying rejection of tniq-owned fields. This goes beyond schema descriptions.

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?

Clearly states 'Update the customer-owned SMS fields on a number you own' with specific resources (inbound webhook URL/secret, fallback URL, MMS toggle). Distinguishes from sibling num_delete_sms_config by noting that tool removes SMS entirely.

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?

Explicitly suggests alternative num_delete_sms_config for removal. Notes that requests with tniq-owned fields are rejected. Error codes are listed. Could add more context on when not to use, but the alternative suffices.

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