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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds useful operational context beyond the annotations in the form of the endpoint and, notably, a cost tier (100 credits, Tier 4). It does not add rate limits or failure behavior, so a 3 is appropriate.

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 with the core sentence, followed by compact bracketed metadata lines. No filler or repetition, though the '[Required: inputs]' line merely restates the schema requirement.

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 explanation is unnecessary, and annotations already cover the safety profile. The description supplies cost and endpoint context, leaving the agent adequately equipped to call this read-only multi-chart calculation tool.

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?

With schema description coverage at 67% and the schema fully documenting the non-obvious fields (timezone, timezoneOffset, houseSystem, ayanamsa), the schema does most of the heavy lifting. The description adds no parameter syntax or format detail, 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?

The description gives a specific verb (Calculate), resource (synastry aspects) and scope (simultaneously across 2–8 charts, returning all pairwise cross-chart aspect matrices). This scope distinguishes it from the 2-chart astroway_relational_synastry, but no sibling is named explicitly.

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 statement of when to pick this tool over astroway_relational_synastry, astroway_relational_synastry_aspect_grid, or astroway_relational_composite. The '2–8 charts' bound and '[Group: Comparisons]' tag hint at multi-chart use but provide no explicit when/when-not guidance.

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