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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds useful metadata by disclosing a 10-credit Tier 1 cost, which is behavioral context not present in annotations, but says nothing about return format or rate behavior.

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 description is brief and front-loads the thematic meaning, followed by compact bracketed metadata. It avoids wasted prose, though the first line is a fragment rather than a complete purpose statement.

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 zero-required-parameter, read-only tool with an output schema and rich annotations, the description does not need to explain return values or safety. However, it still lacks explicit usage guidance and a clear operational purpose, which are the main remaining gaps for an agent selecting among many esoteric 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%, and both parameters (fields, precision) are documented directly in the input schema. The description adds no parameter-level meaning, so the baseline of 3 is appropriate when the schema carries the full burden.

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 names the thematic domain of the life line—vitality, health, life force—but does not state an operation or what the tool actually returns. It distinguishes the life line from other palmistry lines only by association, leaving the purpose vague rather than tautological.

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 guidance on when to use this tool versus siblings such as fate_line, head_line, or heart_line. The group label 'Palmistry (Cheiro)' and credit cost provide context but do not tell the agent when this specific life-line reading is appropriate.

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