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

Annotations already declare readOnly=false, openWorld=true, idempotent=false, destructive=false, so the mutating/side-effecting nature is covered. The description adds genuinely new behavior: the platform is auto-detected from the URL, which the agent cannot infer from annotations. It does not cover duplicate-URL handling, auth requirements, or delivery/verification behavior.

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 sentences, zero padding, and the invocation instruction (paste the URL) is front-loaded before the conditional auto-detection detail. Every clause carries information.

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 five-parameter creation tool with no output schema, the description covers channel support, the URL source, and type resolution, leaving events and secret to the schema. It is nearly complete, though it could note the relationship to send_test_alert for verifying a newly added webhook.

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%, so all five parameters are already documented, including webhook_type's 'Override auto-detection'. The description's supported-platform list adds nuance (any HTTPS endpoint) but largely restates the schema's auto-detection/override relationship, so the baseline of 3 applies.

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 concrete purpose: registering an alert destination across Slack, Discord, Teams, or any HTTPS endpoint, with the mechanism (paste the incoming-webhook URL) spelled out. It implicitly distinguishes itself from sibling notification tools like set_email_alerts and send_test_alert by naming the channel types, but never names a sibling explicitly.

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?

It gives clear operational guidance: paste the URL the user gives you, and pass webhook_type only when overriding auto-detection. That tells the agent the expected invocation pattern. It stops short of stating when not to use this tool or which sibling to prefer for related notification tasks.

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