Create a channel account (custom channel)

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

With no annotations, the description carries the full burden. It discloses the required OAuth scope ('conversations.custom_channels.write') and hints at the behavior of using different delivery identifiers. However, it does not describe side effects, return values, or any restrictions beyond the scope, leaving some behavioral aspects opaque.

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 with no redundant wording. The first sentence states the core action, and the second adds value by explaining the use case and required scope. It is front-loaded and efficient.

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?

Given the tool's moderate complexity (6 parameters, no output schema), the description covers the essential context: purpose, scope, and conceptual usage. It could be more complete by explicitly noting that the inbox and channel must already exist or by describing the response, but the core information is present.

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 coverage is 100%, so the baseline is 3. The description adds some context about delivery identifiers that helps interpret delivery_identifier_type/value, but it does not provide additional meaning beyond what the schema already describes for each parameter.

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 action ('Create a new account') and the resource ('within a specific custom communication channel'). It also explains the purpose ('Enables multiple accounts to communicate over a single channel with different delivery identifiers'), which distinguishes it from update/retrieve 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?

The description implies when to use this tool (when creating a channel account) and provides context about multiple accounts per channel, but it does not explicitly mention alternatives or when not to use it. There is no direct comparison to UpdateChannelAccountInfo or other sibling tools.

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