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

Annotations declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safe-read behavior is already known. The description adds useful specifics: the exact count of 169 targets, the 1–17 goal range, and target code format like '1.1', '3.3', '13.2', which go beyond the 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?

The description is three sentences, each providing distinct value: what the tool lists, the optional filter and code format, and the relationship to a sibling tool. It is tightly written with no filler or repetition of schema content.

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 read-only tool with one optional parameter, a clear output schema, and supportive annotations, the description covers the essential details: the full set of targets, the filtering option, the code format, and the path to indicators. Nothing critical 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?

Schema description coverage is 100%, and the parameter 'goal' is clearly described in the schema ('Filter by SDG goal number... If omitted, all 169 targets...'). The description reinforces the optionality and the range 1–17, which complements the schema without redundancy.

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 explicitly states the tool lists all 169 UN SDG targets with official descriptions, optionally filters by goal number (1–17), and explains the target code format. It clearly distinguishes this from unsdg.goals.list, unsdg.indicators.list, and unsdg.data.query in the sibling list.

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 when to use this tool (to list targets, optionally filtered by goal) and explicitly references unsdg.indicators.list for drilling into measurement indicators, routing the agent to the appropriate sibling tool for the next step.

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