create_subscription

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

Since no annotations are provided, the description carries the full burden. It discloses key behaviors: signed JSON payload with specific fields, ~8s delivery delay, per-subscription secret for signature verification. This is thorough, though it does not address idempotency or rate limits.

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 a single, well-structured sentence that front-loads the purpose and packs in essential details without any fluff. Every word contributes to understanding.

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 has only 2 required parameters and no output schema, the description covers the input, the webhook behavior, and the secret usage. It does not cover error cases or limits, but for a create operation, this is largely sufficient.

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 description adds minimal parameter information beyond what the schema provides. It mentions server-side resolution of the channel, which is a slight addition, but not enough to raise the score above baseline.

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 ('Turn a YouTube channel into a webhook') and the resource, with specific details about the resulting webhook behavior. It distinguishes itself from sibling tools like list_subscriptions and delete_subscription by focusing on creation and the webhook mechanism.

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 the tool (to monitor a YouTube channel via webhook) but does not explicitly state when not to use it or compare it to alternatives. No direct guidance on prerequisites or conditions.

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