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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds meaningful disclosure: delivery history is opt-in and may be absent, and the payload deliberately omits the signing secret and request body. Pagination behavior is not described, keeping it from a 5.

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?

Three compact sentences, front-loaded with the primary list behavior before the secondary view. Every sentence contributes, though 'stays off until it is switched on' is slightly vague about who enables it and pronoun references to 'that history' and 'it' require mild inference.

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 read-only list tool with no output schema, the description compensates by naming the returned fields and the deliberate data omissions. Remaining gaps are pagination semantics and workspace scoping, which the schema exposes only partially and the description does not address.

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 only 40%, so the description must carry weight. It explains the critical enum parameter view and the webhook_id dependency ('webhook ID from view=webhooks') well, but says nothing about limit, offset, or workspace_id, leaving three of five parameters undocumented in both schema and description.

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 opens with a specific verb and resource ('List API webhook subscriptions') and enumerates what is returned (event filters, active state, delivery status), then explains the secondary view=deliveries mode. It is clear what the tool does, but it never explicitly contrasts itself with the sibling manage_webhook or create_webhook, so sibling differentiation is only implied by the verb.

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 useful in-tool guidance: view=deliveries requires a webhook_id taken from view=webhooks, and delivery history is disabled by default so results may be empty. However, it offers no when-not-to-use guidance and does not route the agent to manage_webhook or create_webhook for related operations, leaving alternative selection to inference.

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