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

Annotations already declare the safety profile (destructiveHint=false, openWorldHint=true), and the description adds two genuinely useful facts not in the structured data: the 30-second tick cadence and the 10-credit Tier 1 cost. However it does not explain the streaming lifecycle (how updates are delivered, when the stream ends, why a 'snapshot' is flagged readOnlyHint=false and non-idempotent), leaving the non-readonly flag unexplained.

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-loaded one-line purpose followed by compact bracketed metadata; nothing is padded. The bracketed lines are boilerplate but carry real cost/endpoint information, so they earn their place.

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-value detail is not required. Still, for a non-readonly streaming tool the description omits lifecycle semantics (duration, termination, billing per tick vs per call), which 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 description coverage is 100% and both parameters (fields, precision) carry detailed descriptions with examples, so the schema does the heavy lifting. The description adds no additional parameter meaning, 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 concrete resource and verb-equivalent: a snapshot of current planetary positions, with the tick cadence. It is distinguishable from sibling streams (ingress, retrograde alerts, void-of-course) by being the general positions feed, though it never explicitly names what separates it from astroway_mcp_streaming or astroway_stream_transit_alerts.

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?

There is no when-to-use guidance at all: no condition selecting this stream over the other stream_* siblings or over astroway_mcp_streaming, and no stated prerequisite. Only endpoint, group and credit cost are given, which is operational metadata rather than usage routing.

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