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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It explicitly lists the returned metrics (vessel counts, congestion score, port status) and the full list of covered ports, which informs the agent about the fixed scope. It does not explicitly state 'read-only,' but the verb 'monitor' and the absence of side-effect language imply a safe read operation. It also discloses the real-time nature and historical baseline comparison, providing 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 at two sentences, yet it packs in purpose, output details, port coverage, and target users. Every sentence adds meaningful information, and the structure flows logically from function to output to use cases.

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 tool with zero parameters, no output schema, and no annotations, the description is remarkably complete. It explains the tool's purpose, the exact data points returned, the geographic coverage, and the intended audience. No critical information appears missing for an agent to decide when and how to invoke it.

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 schema coverage is trivially 100% and the description need not explain parameter syntax. The description adds value by specifying the fixed set of 26 ports and the return fields, which helps the agent understand what the tool will retrieve without any inputs.

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 states the tool's function with a specific verb ('Monitor real-time port congestion and vessel traffic') and resource (26 major global ports). It also specifies the exact outputs: vessel counts at berth and anchor, congestion score vs historical baseline, and port status. This makes the purpose unambiguous and distinct from the generic sibling names.

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 provides clear use context: 'Used by freight forwarders, logistics teams, and importers to monitor delays, plan routing, and anticipate lead time changes.' However, it does not explicitly mention when not to use this tool or compare it to alternatives like get_port_congestion_trends, so it lacks explicit exclusions but still gives a strong sense of when it applies.

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