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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description goes beyond them with the credit cost (500 credits, Tier 6) and an explicit human-confirmation requirement, which is genuinely useful pre-invocation context not present in the schema.

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 core purpose is stated first in a single efficient sentence, with cost/required-parameter metadata bracketed below. The tag block is somewhat redundant scaffolding, but nothing is verbose or padded.

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 an 8-parameter, nested, heavy-cost tool, the description omits how the search window is controlled and how this differs from the rectification_trutine sibling. An output schema exists so return values need no explanation, but the invocation-shaping gaps remain significant.

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 only 38% across 8 parameters, so the description carries a compensation burden it does not meet. It gestures at 'events' and 'transit/direction hits' but says nothing about the search-window controls (searchRangeMinutes, stepMinutes, orb, methods) that are central to narrowing a birth time.

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?

Specific verb ('Rectify') plus resource ('approximate birth time') and the mechanism ('life events and transit/direction hits') make the operation unambiguous. However, it does not distinguish itself from the near-identical sibling astroway_prognostics_rectification_trutine, which an agent would need to choose between.

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 implies the use case (you have an approximate birth time and known life events) and adds an explicit operational guard ('Heavy — confirm with user before invoking'). It never states when to prefer this over rectification_trutine or other prognostics tools, so routing is left to inference.

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