skypeek: sunrise, sunset, twilight and moon phase

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

Goes well beyond the readOnly/idempotent annotations: computed locally with no upstream call, accuracy bounds (~1 min sun, ~3 min moon), explicit limitations (sea-level horizon, no terrain/weather), 422-not-charged behavior, latency (<0.2 s), price, and free tier. This is rich behavioral context an agent needs.

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?

Front-loads purpose and is dense but every sentence earns its place (accuracy, limits, errors, cost, docs). Slight redundancy from the repeated 'skypeek:' brand prefix and a long single paragraph prevent a 5.

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 4-param tool with an output schema and full annotation coverage, the description supplies accuracy, failure mode, cost, latency and a docs link, leaving nothing an agent needs to call it correctly.

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 100%, so the schema already documents lat, lon, date and tz. The description reinforces the point/date/timezone framing but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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+resource set (sunrise, sunset, twilight, moonrise, moon phase) for a place and date, and explicitly distinguishes itself from satellite_passes. An agent can tell exactly what this returns without opening the schema.

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?

Names the alternative (satellite_passes) for orbital-pass queries, giving an explicit routing rule. However, it offers no other when/when-not guidance (e.g. astronomical vs. weather-based needs), so it falls just short of a full 5.

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