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 only a cost tier; it says nothing about what the 'lord' depends on, whether targetAge changes the result, or how it relates to the natal chart supplied.

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?

It is short and front-loaded with no padding, but 'concise' here shades into under-specified: one sentence plus two bracketed tags that carry no task 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?

For a domain-specific Hellenistic technique with a required natal chart plus a targetAge selector, the description never explains the technique, the age range semantics, or expected output, even though an output schema exists to cover return values. The agent cannot judge what this tool produces relative to its many 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%, so the rich body/date/time/coordinates/timezone documentation is already in the schema. Baseline 3 applies; the description contributes no parameter meaning of its own, not even for targetAge.

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?

"Predictive significator selection" names the astrological operation but gives no verb and no resource scope; an agent cannot tell what the tool computes or returns. The sibling astroway_hels_lord_of_prediction is an obvious near-duplicate and is not distinguished in any way.

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, when-not-to-use, or alternative guidance. The group and cost tags describe billing metadata, not invocation conditions, so the agent is left to infer everything from the name.

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