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

Annotations already cover the read-only, idempotent, non-destructive nature. The description adds meaningful behavioral information beyond annotations: it costs $0.001 USDC per call, which is important for cost-aware agents. It also clarifies that it returns server time plus offset, which is useful 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?

Three short, information-dense sentences cover function, usage rationale, cost, and endpoint equivalence. There is no filler or repetition, and the most important behavioral detail (clock-drift purpose) is front-loaded.

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-parameter, read-only clock endpoint with a detailed output schema, the description is complete. It explains what the tool returns, why it matters, the cost, and even an alternate endpoint representation. An agent has everything it needs to invoke and interpret this tool correctly.

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, and the schema description coverage is 100%, so the schema already fully documents the input surface. The description adds no parameter-specific detail, but with 0 params the baseline is 4 and nothing more is needed.

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 a specific resource (Coinbase exchange clock) and the exact value it provides: the venue's server time plus offset against this server, used to prevent clock-drift order rejection. This distinguishes it from the many other market_* sibling tools, especially the other market_cbex_* 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?

The description states the practical context for use: it is the check that stops a signed order being rejected for clock drift, implying it should be called before signing orders. It does not explicitly name alternatives or when not to use it, but the context is clear enough for an agent to select it appropriately.

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