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

Annotations already declare this a safe, idempotent, closed read, so the safety burden is off the description. The description adds real behavioral context the annotations cannot carry: the output is a structured count/label rather than a score, and it costs 50 credits (Tier 3), which matters for tool selection in a large catalog.

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?

Three tight sentences, front-loaded with the method and scope, with the disambiguating negation placed before the metadata tags. Nothing is padding; every clause adds selection-relevant information.

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 the description still covers what is computed, the label vocabulary, the cost tier and the not-a-score caveat. For a two-chart read-only analytical tool this is sufficient to invoke correctly.

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% and the nested chart1/chart2 objects carry unusually thorough field docs (timezone handling, houseSystem letters, rejected short forms), so the baseline of 3 applies. The description only implies 'both partners' maps to the two chart objects and adds no format or constraint detail beyond 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?

Names a specific technique (Bhrigu Sanhita 7th-house planetary placement), the exact computation (counts benefic/malefic planets in each partner's 7H from Lagna) and the output label set. The closing 'NOT a numerical match score' explicitly separates it from the dense cluster of compatibility siblings like vedic_compatibility_ashtakoot, dashakoota and relational_match_score.

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 negative statement 'NOT a numerical match score' tells the agent when this tool is the wrong pick, which implicitly routes scoring requests to the ashtakoot/match-score siblings. However, it never names the alternative or states positively when to choose a Bhrigu placement read over a koota score, so the agent must infer the routing.

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