Group Synastry

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely useful metadata: endpoint, required parameter, and 100-credit Tier-4 cost. It does not disclose anything about output volume for the pairwise matrix explosion or any throttling, and its '2–8 charts' framing conflicts with the schema's minItems 2 / maxItems 10.

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 purpose sentence is tightly front-loaded with verb, scope, and return shape, and the bracketed metadata lines are scannable. The only inefficiency is the 2–8 figure that should match the schema's 10.

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?

With a rich nested schema, output schema, and full annotations, most of the burden is already carried elsewhere, and cost/endpoint add value. But the chart-count inconsistency and the absence of any guidance on what the pairwise matrix contains or how large it gets leave a gap for a tool whose output grows combinatorially.

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?

Top-level schema coverage is 0% (the `inputs` array itself has no description), so the description carries some burden; it names `inputs` as required and gives a size range. That range (2–8) contradicts the schema's maxItems of 10, which is a real semantic hazard, though the nested birth-data fields are very thoroughly documented inside the schema.

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 synastry aspects") plus scope ("among 2–8 charts simultaneously") and output shape ("all pairwise cross-chart aspect matrices"). An agent can distinguish this from single-pair tools such as astroway_relational_synastry, though it never names that sibling explicitly, so it falls short of a 5.

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?

The '[Group: Comparisons]' tag and '2–8 charts simultaneously' imply multi-chart use, and the cost line gives a budget signal. However, no tool is named as the alternative for two-chart synastry or for aggregate scores (astroway_relational_match_score), and no explicit when-not condition is given.

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