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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so safety is covered. The description goes further with lifecycle and cost context the annotations omit: RED data quality, sunset date, the 2017 stability-policy window, and a 10-credit Tier 1 cost. This is genuinely useful operational context beyond the structured fields.

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?

The core purpose sentence is front-loaded after a deprecation preamble, which is the right ordering. However, the deprecation is stated twice – once as the "DEPRECATED: RED quality" prefix and again in the bracketed "[⚠️ DEPRECATED — will be removed...]" block – and the [Group]/[Endpoint]/[Required] boilerplate is largely redundant. Some trimming would earn more of its space.

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 needn't be explained. The description covers purpose, deprecation timing, migration, required input, and cost – everything an agent needs to decide and invoke. The absence of a named successor endpoint is the only real gap.

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 67%, and the schema already documents both `fields` and `precision` in detail with examples. The description only restates the required `date` ("for date") without adding format, range, or semantics beyond the schema's pattern. Baseline 3 is appropriate when the schema carries the detail.

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?

"Calculate Djamaspa planetary positions for date" gives a specific verb+resource and the input it needs. The esoteric/Djamaspa subject matter distinguishes it from the geomancy, runes, and mayan siblings, though it doesn't explicitly contrast with a near-neighbor tool. Clear enough for selection despite the deprecation noise surrounding it.

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?

Explicitly tells the agent not to use it ("Avoid using", "DEPRECATED") and provides a migration route ("Migrate to broader /reference endpoints or remove the dependency") plus a hard sunset date. This is strong when/when-not guidance. It doesn't name a specific replacement endpoint, which keeps it from a 5.

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