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

Annotations already declare readOnly=false, idempotent=false, destructive=false and openWorld=true, so the safety profile is covered. The description usefully adds the cost (10 credits, Tier 1) and the endpoint, but omits behavior an agent would want: that repeated calls create duplicate registrations (idempotentHint=false), that url must presumably be publicly reachable/HTTPS, and what registration returns. With annotations carrying the main load, a 3 is appropriate.

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 definition is short and front-loads the event trigger, followed by compact bracketed metadata (group, endpoint, required, cost). No sentence is wasted, though the bracket block is somewhat skeletal rather than explanatory.

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 described, and endpoint/cost/required are present. Gaps remain for a webhook-registration tool: the undefined 'N days' is never explained or tied to a configurable parameter, and the relationship to astroway_webhooks_subscribe (does it need to be called first?) is unstated. Adequate but with clear holes.

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 a middling 67%: fields and precision are documented in the schema, while url carries only type/format with no description. The description's '[Required: url]' merely restates what the schema already marks as required and adds no constraint details (scheme, reachability, retry expectations). Baseline 3 is right since the schema does most of the parameter work.

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 the trigger event ('Fires N days before a Vimshottari mahadasha ends') but never names the actual action of the tool, which is registering/subscribing a webhook. Grouping it under [Group: Webhooks] and the endpoint tag help the agent infer intent, but the wording describes an event rather than a create/subscribe operation. It also does not differentiate from the closely related sibling astroway_webhooks_dasha_change.

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 trigger condition ('N days before a mahadasha ends') implicitly signals when this webhook is relevant, which is a form of usage context. However, there is no explicit when-to-use, no when-not-to-use, and no routing to alternatives such as astroway_webhooks_dasha_change or astroway_webhooks_subscribe. Whether a generic subscribe call is a prerequisite is left entirely to inference.

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