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 does add useful operational context beyond the annotations: the concrete endpoint (POST /v1/palmistry/marriage-line) and the billing cost of 10 credits (Tier 1), which matters for an agent deciding whether to call it. It still says nothing about what the tool actually computes.

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 text is short and the metadata lines are orderly, but the actual purpose sentence is a two-word fragment that carries almost no information, while half the description is spent on bracketed admin metadata. Nothing is bloated, but the single content sentence does not earn its place as a 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?

With zero required parameters and an output schema present, return format is rightly omitted, but the description never explains what the tool consumes (palm image? line data? nothing?) or what interpretation it produces beyond 'significant partnerships.' For a tool with no required inputs, failing to say what the call actually does leaves a real 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 100% and both parameters (fields, precision) are output-shaping/compact-mode options that the schema documents thoroughly. The description adds nothing about them, which is acceptable here, so the baseline of 3 applies.

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 is a bare noun phrase, 'Significant partnerships,' which restates the meaning of the title 'Marriage Line' rather than stating a verb and resource (e.g. 'interpret the marriage line in a palm reading'). It gives no sense of what the tool operates on and does not distinguish it from the sibling palmistry lines (heart_line, fate_line, life_line).

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 routing guidance of any kind; the agent is left to infer from the name alone that this is the marriage-line counterpart to the other palmistry line tools. The only extra information is administrative (group, endpoint, cost).

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