Coinbase Premium (US demand gauge) + carry yield

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

Annotations already declare read-only and open-world hints. The description adds meaning beyond this: positive premium equals US buying pressure, history since 2017, and the specific metrics returned. No contradictions and no hidden behaviors.

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?

Three sentences, front-loaded with the call trigger, and every clause is informative. No filler or redundancy; it efficiently packs purpose, output details, and interpretation.

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 zero parameters and no output schema, the description fully compensates by enumerating the output fields and time horizons. It provides enough context for an agent to invoke the tool and interpret results, even fitting in historical depth and semantic meaning.

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 schema baseline is 4. The description goes beyond by explaining the semantics of the returned data (premium percent, buy pressure), which is valuable even though parameters are absent.

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 identifies the tool as a Coinbase Premium indicator for US buying/selling pressure and cash-and-carry yields. It specifies exactly what it returns (daily premium, 7-day average, streak, 30 days, carry yields) and distinguishes it from siblings like funding or pressure tools.

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?

Explicitly states when to call: when the user asks about US investor buying/selling, Coinbase Premium, or cash-and-carry basis trade. It does not mention exclusions or alternatives, but the context is clear enough to avoid mis-selection among siblings.

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