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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds useful non-schema context: the return is a compact topic-to-id map and the identical content is available as a static resource at a known URL, letting the agent avoid a call entirely. It doesn't detail pagination or size limits, but for a static map that is a minor gap.

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 short sentences with the content shape front-loaded and the action guidance second. Zero filler; the URL is the only extra token and it enables skipping the call.

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?

With no input parameters and no output schema, the description must carry the return-shape burden, and it does so at a high level ('topics -> fact ids (doc#n) and docs') plus a URL mirror. It stops short of explaining the map's size or format details, which would help an agent decide whether to ingest it.

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 takes zero parameters, so the baseline is 4. The description correctly implies the call is argument-free by describing a fixed, complete map, and adds no misleading parameter information.

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 names the resource (a compact map of topics to fact ids and docs) and specifies the exact content shape ('doc#n'), so an agent knows what it retrieves. It distinguishes itself from siblings by framing itself as a planning artifact rather than a query tool, though 'atlas' itself is a coined term that carries no meaning without the description.

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 gives a concrete use case — 'Use to plan which ask/read_note calls to make' — explicitly naming the alternatives it precedes. It does not state when not to use it (e.g., versus search_notes or list_notes), but the routing intent is clear.

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