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

Annotations already declare readOnly, idempotent, non-destructive, open-world. The description adds the pricing mechanics (0.03 USDC x402 on Base) and the data source (IMF PortWatch satellite AIS, free, no key), which is genuinely useful beyond annotations. It doesn't disclose freshness/cadence beyond 'daily' or failure modes, so it is solid but not rich.

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?

Front-loaded with the value proposition, which is good, but the tail is dense and the pricing is stated twice ('$0.03 USDC x402 Base' and '[x402: 0.03 USDC per call on Base]'), which is redundant. The single long em-dash sentence is harder to scan than it needs to be.

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 read-only, single-param, no output-schema tool, the description covers source, scope, signals, timeliness rationale, and cost — enough for an agent to decide and call. It omits response shape and error/coverage caveats, which keeps it just under complete.

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 coverage is 100% and there is only one parameter, so the baseline is 3. The description mentions presets (Shanghai, Singapore, Rotterdam, LA, Long Beach) and 'any name', which gives useful domain context for what the 'port' field should contain — but the schema already documents the parameter, so no lift above baseline.

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?

States a specific verb and resource — 'daily port activity' across a named universe of 2,065 ports — and enumerates the concrete signals returned (port calls, dwt capacity, 7d vs 30d anomaly). The IMF PortWatch framing and 'leads official macro data by weeks' positions it distinctly from siblings like volume_anomaly or gdelt_tension.

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?

Gives a clear use context — 'the input for trade/tariff/recession markets' — and implies when to reach for it via the lead-time argument. It does not name an alternative or state exclusions (e.g., vs volume_anomaly), so it falls short of a 5.

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