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

Annotations already establish readOnlyHint and openWorldHint, but the description adds a meaningful behavioral boundary: it explicitly forbids cross-lane drug, actor, route, guilt, political, project, causal, tactical, and navigable inference or use. This is valuable context beyond the structured annotations, clarifying the tool's limited analytical scope.

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 with no filler. The main action is front-loaded, and the second sentence crisply adds the key restriction. Every word earns its place.

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 parameterless read tool with an output schema defined, the description fully covers purpose, scope, and the critical behavioral constraint. There is nothing an agent needs to know to invoke it correctly that is missing.

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 fully covers the interface. Per the baseline for parameterless tools, a score of 4 is appropriate; no further parameter explanation 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 states the verb 'return' and the specific resource: pinned source readiness and national WDI coverage for CPEC, Gwadar, CMEC, Kyaukpyu, and Balochistan. It also frames this as a 'parallel context lane,' which distinguishes its scope from siblings like bridge or corridors.

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?

It provides a negative guideline—prohibiting cross-lane inference—but never explicitly compares itself to sibling tools or states conditions for when to choose it over them. The usage context is implied but not directly spelled out.

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