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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is fully covered without the description. The description adds no behavioral context of its own: no scope (which subscriptions — credential-wide or filtered), no pagination, no ordering, nothing beyond what annotations and the schema already convey.

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?

A single short, front-loaded sentence with no filler or repetition. It is efficient, though its brevity is partly achieved by omitting content rather than by tightening it.

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?

An output schema exists, so return values need not be explained, and annotations cover safety. What is still missing is any statement of scope — whether this lists all webhook subscriptions for the credential or supports filtering — which matters for a list tool in a 130-tool namespace.

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% with a single optional approval_id fully documented in the schema, so the baseline of 3 applies. The description adds no semantics about the parameter or about what an unfiltered call returns.

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 gestures at the resource ('real-time notifications... set up') but never states the operation or resource name — it reads as a when-to-use clause rather than a statement of what the tool does. An agent must infer from the name 'webhooks.list' that this returns webhook subscriptions. It is not misleading, just vague.

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 entire sentence is a usage trigger ('When you want to see...'), which is implied guidance, but it is circular — it says to use the tool when you want what the tool does. It draws no boundary against webhooks.create or webhooks.delete, and gives no conditions, scoping, or prerequisites.

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