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

Annotations declare the safety/lifecycle profile (not read-only, not idempotent, open-world, non-destructive), so the description need not restate it. It does add context the annotations lack – group membership and a 10-credit Tier 1 cost – but says nothing about how the stream behaves (push vs. poll, cadence, termination). Modest value-add over structured data.

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?

Extremely short and front-loaded, with group and cost metadata cleanly bracketed. Nothing is padded, though the terseness shades into under-specification rather than true economy.

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?

An output schema exists, so return shape is covered, but for a 5-parameter streaming tool with minimal annotations the description omits usage routing, streaming behavior, and meaning for the required coordinates. Too thin for correct invocation.

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 60%, and critically the two REQUIRED parameters (latitude, longitude) have no schema description at all. The description supplies no coordinate semantics, no units, and no guidance on timezoneOffset interplay, so it fails to compensate for the coverage gap on the most important inputs.

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?

"Current planetary hour + next 24" names the resource (planetary hour) and the window (next 24), and the group tag confirms it is a streaming tool. But "next 24" is ambiguous (24 hours vs. 24 changes) and there is no verb framing what is returned. It identifies the subject without cleanly differentiating it from siblings like astroway_stream_positions or astroway_webhooks_planetary_hour_tick.

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?

No when-to-use, no when-not-to-use, and no named alternative among the many stream/webhook siblings. The agent must infer from the group tag that this is a live-feed tool and cannot tell when to prefer it over a webhook subscription or a positions stream.

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