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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds value beyond them by disclosing cost ('10 credits (Tier 1)') and the Group: Core classification, which matters for budgeting. It does not discuss rate limits, caching, or determinism, so it falls short of a 5.

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?

One tight sentence plus two bracketed metadata tags, with the core purpose and the scope exclusion front-loaded. Nothing is padded or repeated.

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 values need not be explained, and annotations carry the safety profile. Still, for a 15-parameter tool the description says nothing about how zodiacType/ayanamsa change the returned longitudes or what houseSystem does, leaving real gaps for an agent assembling a call.

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?

The description mentions no parameters at all, while schema description coverage is only 33% across 15 parameters. Although the schema documents the trickiest inputs (timezone, timezoneOffset, ayanamsa, fields, precision), others such as houseSystem's single-letter enum, zodiacType, and cosmogram are undocumented anywhere, and the description does nothing to compensate.

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 ('Calculate raw planet longitudes') plus the input context ('for a given date/time'), and scopes it by what it excludes ('without full chart context (no houses, no aspects)'). That exclusion implicitly separates it from astroway_western_chart, so an agent can pick between the two without opening a 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?

Gives clear context for when this is the right call: a lightweight longitude-only computation for a date/time. It never names an alternative tool or states a hard when-not rule, so the agent must infer that houses/aspects needs route elsewhere.

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