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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds value by specifying that channels can be Slack, Discord, or generic webhooks, which clarifies the expected content. However, it does not disclose potential behaviors like pagination or ordering, but for a zero-parameter read-only tool the bar is low and the description covers the essential 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?

The description is a single, front-loaded sentence that immediately states the action ('List all webhook notification channels') and the scope. No wasted words, and the specific channel types (Slack, Discord, generic webhooks) are included in a compact manner.

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 simple read-only list tool with no parameters and no output schema, the description is complete. It tells the agent what the tool does and what kind of data to expect (channels, their types). There is no missing information that an agent would need to call it correctly, given the readOnlyHint annotation and the absence of parameters.

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?

There are zero parameters, so the schema provides complete coverage trivially. The baseline for 0 params is 4, and the description adds no additional parameter semantics because none exist. The mention of 'for your account' is a scope qualifier but not a parameter, so the score stays at 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 states a specific verb ('List'), a clear resource ('webhook notification channels'), and a scope ('for your account'). It distinguishes itself from sibling tools like create-notification-channel and delete-notification-channel by focusing on listing, so an agent can infer the correct tool without ambiguity.

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 clearly implies when to use this tool: when you need to see all existing webhook notification channels. It does not explicitly name alternatives or exclusion criteria, but the simple read-only nature and sibling tool names (create/delete/disable/enable/test) make the intended use obvious. Slight deduction for not explicitly stating 'use this for overview, use create-notification-channel for adding'.

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