space.observe

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

With no annotations, the description carries full burden. It details the computation (JPL elements, validated vs Horizons) and outputs (RA/Dec, magnitude, altitude/azimuth, visible-now flag, viewing window). No mention of side effects, but for a read-only query, it is adequately transparent.

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?

Two sentences with no wasted words. The first sentence covers the core purpose and outputs; the second adds optional observer-location features. Very front-loaded and efficient.

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?

Without an output schema, the description thoroughly explains what the tool returns. It covers both geocentric and observer-based outputs. It could mention error handling for invalid bodies, but for a straightforward query tool, it is sufficiently complete.

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 only 20% (only 'body' has a description). The tool description explains that 'lat' and 'lon' are for observer location to get altitude/azimuth, and implies 'at' for viewing window, but 'altKm' is not mentioned. Description adds value but does not fully compensate for low schema coverage.

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 clearly states it propagates JPL orbital elements to give geocentric RA/Dec, constellation, etc. It distinguishes from sibling tools like space.body or space.close-approaches by focusing on sky visibility and viewing windows.

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 opens with 'Where is an asteroid/comet in the sky and can you see it?' which clearly indicates when to use. It does not explicitly state when not to use or list alternatives, but the context is clear.

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