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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description nonetheless adds real behavioral context beyond them: retrograde re-entries are included in results and the call costs 100 credits (Tier 4), which is a material resource constraint an agent should weigh.

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 purpose sentence is front-loaded and wastes nothing, and the bracketed metadata block (group, endpoint, required, cost) is scannable. Minor redundancy in re-listing required parameters that the schema already declares.

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, return values need not be explained, and the description supplies purpose, required inputs, endpoint and cost. The remaining gaps are sibling differentiation and planetId/date semantics, which are minor for a read-only lookup 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 description coverage is only 40%: planetId, startDate and endDate carry no descriptions, while fields and precision are documented in the schema. The description's '[Required: planetId, startDate, endDate]' merely restates the schema's required array and adds no format or semantic detail (e.g. planetId encoding), so it does not compensate for the coverage gap.

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?

States a specific verb and resource ('Find all sign ingresses for a planet') with a scoping qualifier ('within a date range') and clarifies that retrograde re-entries are included. This is clear and distinguishable from the calendar family at a glance, though it never names a sibling (e.g. retrograde_periods) to sharpen the boundary.

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?

Usage is implied by the planet + date-range framing, so an agent can infer when the tool applies. However, there is no explicit when-to-use/when-not guidance and no routing to alternatives such as astroway_calendar_retrograde_periods or astroway_calendar_planetary_cycles, which are the closest overlapping siblings.

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