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

Annotations already declare readOnly/idempotent/non-destructive, so the safety bar is low. The description adds genuinely useful behavior beyond them: it validates against a held-out event and explicitly caps expectations ('never claims an exact recovered minute'). It does not mention runtime cost or how candidate ranges are enumerated.

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?

Two sentences, no filler, with the core action front-loaded and the important accuracy caveat last. Every clause earns its place.

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 need not be described, and the behavioral caveat is covered. However, for a 6-parameter tool with a nested required object at 0% schema coverage, the description leaves the agent guessing about input shape, which is a real completeness 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 0% across 6 parameters, so the description must compensate and largely does not. It hints at the events array and holdoutEventId, but baseInput (a nested object), stepMinutes granularity, and the string format/bounds of earliestTime/latestTime are entirely unexplained.

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+resource ('scores candidate birth times') plus the mechanism (against life events, validated with a held-out event). It is easy to distinguish from the analysis-heavy siblings, none of which do birth-time rectification. It stops short of a 5 only because the domain scope (which chart/ayanamsa) is left implicit.

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 description implies usage (you have uncertain birth times and known life events), but never states when to reach for this tool versus e.g. audit_chart_calculation or assess_prediction_readiness, and gives no preconditions such as needing a sufficient event count. Usage is inferable but not guided.

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