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

No annotations are provided, so the description carries the full burden. It describes the operation as returning detailed info, implying read-only, and lists output fields. It does not explicitly declare idempotency or absence of side effects, but for a get operation this is sufficient. A 4 reflects good transparency without being exhaustive.

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?

Two sentences, front-loaded with the return value list, followed by lookup method and alternative. No wasted words; every sentence earns its place. Very concise and well-structured.

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 simple get tool with full schema coverage and an output schema, the description adequately covers what is returned, how to query, and when to use an alternative. No additional context (error handling, auth) is necessary for this straightforward operation.

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 input schema already has descriptions for both parameters with 100% coverage, including the mutual exclusivity hint. The description restates this ('exactly one') but adds no new semantic value beyond what the schema provides. Hence a baseline 3.

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 returns detailed information for a single port, listing specific fields (identity, country, UN/LOCODE, etc.). It explicitly distinguishes from find_ports, which is for search by name or location, leaving no ambiguity about this tool's purpose.

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 explains exactly when to use this tool (when you have a Datalastic uuid or UN/LOCODE) and when not to (for name/location search, use find_ports). This provides clear context against siblings and gives an alternative.

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