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

Annotations already carry readOnly, openWorld, idempotent, and non-destructive hints. The description adds that results include official titles and full descriptions, and that goal codes are reusable as inputs to other tools—useful content-level context. No contradictions with annotations.

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?

Three sentences with the core purpose front-loaded. The 17-goal enumeration is slightly long but earns its place by confirming complete coverage, and the final sentence provides a useful cross-tool pointer. Nothing is redundant with the schema or annotations.

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?

This is a simple read-only list tool with zero required parameters, an output schema, and rich annotations. The description covers purpose, scope, content of results, and downstream usage. Nothing an agent needs to call it correctly 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 only parameter, locale, is fully described in the input schema including default and supported values ('en' only). Schema description coverage is 100%, so the baseline of 3 applies even though the description itself says nothing about parameters.

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 opens with a specific verb and resource: 'List all 17 UN Sustainable Development Goals (SDGs) with their official titles and full descriptions.' It enumerates every goal, making the scope completely unambiguous. The sibling tool names (targets, indicators, data, geo) confirm this is the goals-specific list, so differentiation is clear.

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 third sentence gives explicit routing guidance: 'Use goal codes (1–17) as inputs to unsdg.targets.list and unsdg.indicators.list.' This tells the agent how to chain this tool into related ones. It does not explicitly state when to prefer this over unsdg.data.query or unsdg.geo.countries, leaving slight room for inference.

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