Coinbase Premium (US demand gauge) + carry yield

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

Annotations already declare readOnlyHint and openWorldHint, so the description adds value by detailing the output fields (daily premium, 7-day average, streak, last 30 days, carry yields) and the interpretation of positive premium as US buying pressure. No contradiction; it supplements the annotations with useful behavioral context.

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 concise (four sentences), front-loaded with the usage trigger, then return values, then historical depth and interpretation. Every sentence contributes valuable information without redundancy.

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?

Given no output schema and no parameters, the description fully covers what the tool returns (latest premium, averages, streaks, 30-day history, carry yields) and how to interpret it. It also mentions historical coverage since 2017, making it complete for this straightforward tool.

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?

The tool has zero parameters, so the baseline is 4. The description does not need to explain inputs and instead focuses on output semantics, which is appropriate and sufficient for a parameterless tool.

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 clearly defines the tool as a gauge for US buying/selling pressure via Coinbase Premium, explicitly naming the metric and the related carry yield. It distinguishes from siblings by referencing specific topics such as Coinbase Premium and cash-and-carry basis trade, which are unique among the sibling list.

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?

Provides explicit trigger conditions ('Call this when...') for user queries about US investor activity, Coinbase Premium, or carry trade yield. However, it does not mention alternatives or when not to use this tool, so it lacks exclusionary guidance that would elevate it to a 5.

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