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

Annotations already declare the key traits (readOnlyHint=false, openWorldHint=true, idempotentHint=false), so the agent knows this is an outbound mutating registration. The description adds payload semantics (fires on planet ingress), the endpoint, and the 10-credit cost, which is real added value. It omits important behavior for a non-idempotent registration: whether repeated calls create duplicate hooks, whether a signing secret or webhook ID is returned, and how to subsequently inspect or remove it.

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 tight — one sentence plus four bracketed metadata lines — and the cost and endpoint are front-loaded where an agent will see them. Nothing is wasted, though the single prose sentence is spent on the event rather than on the registration action.

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?

With an output schema present and annotations covering the safety profile, the description does not need to explain return values, and it usefully supplies endpoint, required param, and credit cost. Remaining gaps (lifecycle management, non-idempotent duplicate behavior) are modest for a simple one-required-param registration tool.

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 67% and the two optional parameters (fields, precision) are well documented in the schema itself, so baseline credit applies. However the one required parameter, url, has no description in the schema beyond format:uri and maxLength, and the tool text only echoes "Required: url" without clarifying it must be a publicly reachable HTTPS receiver. It neither compensates for nor harms the schema.

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 lead sentence, "Fires when any tracked planet ingresses a new sign," describes the event payload rather than the action the tool performs — registering a webhook subscription. The action is only inferable from the title and the "POST /v1/webhooks/sign-ingress" endpoint line, not from the prose. It also does not distinguish this from the sibling astroway_stream_ingress, which delivers the same ingress event via streaming.

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?

There is no explicit when-to-use guidance, no statement of when to prefer this over the stream_ingress sibling, and no mention of the related webhook lifecycle tools (astroway_webhooks_id, astroway_webhooks_id_test). The only operational cues are "Required: url" and the cost line; an agent must infer the rest.

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