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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile needs no restatement. The description adds genuinely useful behavioral context in the cost line (10 credits, Tier 1), but says nothing about output shape, whether both birth charts are mandatory inputs, or scoring semantics — acceptable but thin given annotations carry the safety burden.

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 is front-loaded in the first line and the two bracketed metadata lines are short and informative, with no padding. It is extremely terse, but nothing present is redundant.

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?

Rich schema (100% coverage, nested founder/partner objects), an output schema, and full annotations mean the description need not explain inputs, returns, or safety. What remains missing is the usage/routing context, so it is only minimally adequate for a tool with many near-neighbor compatibility siblings.

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%, with the founder/partner objects, fields, and precision all documented in the schema itself, so baseline 3 applies. The description only implies two people are supplied and adds no syntax, default, or interpretation detail beyond the structured fields.

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 resource and pairing ("Founder × partner compatibility score") and the Business Astrology group tag frames it as a business-context compatibility calculation, distinguishing it from the broader relational/synastry siblings. It stops short of naming any sibling it should be chosen over, so it is clear but not fully differentiated.

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 mention of when a business team compatibility read is appropriate versus astroway_relational_synastry, astroway_business_ideal_partner_sign, or other compatibility tools, and no preconditions stated. The only contextual metadata is the group and credit cost, which is not usage guidance.

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