List live digital twin scenes

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 real behavioral value by disclosing the return shape (per-twin link and embed link, plus a builder link) and the data layers behind each twin. It does not contradict either annotation. It could still say more about link validity or whether the builder link requires auth, so a 4 rather than 5.

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, each doing work: catalog contents, return shape, and usage trigger, with the core resource front-loaded. The parenthetical data-source list is slightly long but is genuinely informative about what the twins show.

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 parameters and no output schema, the description carries the burden of describing returns, and it does so (links, embed links, builder link). Read-only behavior is confirmed by annotations. The only gap is that it does not say whether results are static/constant or whether the builder link is account-bound.

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 and there is nothing for the description to compensate for. The description correctly implies a fixed, unfiltered catalog rather than suggesting any filtering options.

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 the ready-made city digital twins'), names the concrete instances (Barcelona, Helsinki, Tokyo), and enumerates what each entry contains (IFC models, OSM city, live open-data layers, links). No sibling tool in the list does anything similar, so an agent can distinguish it immediately.

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 states an explicit trigger: 'Use it when the user asks for a digital twin demo or wants to start one,' and covers the adjacent builder use case. It stops short of naming an alternative tool or stating when not to use it, which keeps it below a 5.

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