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

Annotations already indicate readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds behavioral context by specifying that setting the goal parameter returns nested targets and indicators, which is consistent with annotations and provides extra detail about the response structure.

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 a single sentence that efficiently conveys the main purpose and optional behavior. It is front-loaded with the action and resource, with zero wasted words.

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?

Given no output schema, the description adequately explains what is returned (code, title, description for all goals; plus targets and indicators if drill). The tool is simple with one optional parameter, and the description covers the essential information for an AI agent to use it 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?

Schema coverage is 100%, and the description adds meaning by explaining that if the optional goal parameter is set, it returns that goal with its nested targets and indicators; otherwise, it returns all 17 goals. This clarifies the conditional behavior beyond the schema's description.

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 it lists the 17 UN Sustainable Development Goals with their code, title, and description, and optionally drills into one goal for targets and indicators. It uses specific verb 'List' and resource 'UN Sustainable Development Goals', distinguishing it from sibling tools like list_indicators.

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 indicates when to use the optional goal parameter - to drill into one goal for targets and indicators, versus listing all goals. It does not explicitly state when not to use the tool or compare to alternatives, but the context of sibling tools implies differentiation.

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