List the ERC-4626 vaults this server can see

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

Annotations already declare readOnly, openWorld and non-destructive, so safety is covered. The description adds real behavioral context beyond that: it discloses the multi-subgraph fan-out, that results are per-subgraph index progress, and that unreachable subgraphs are surfaced rather than silently dropped — a partial-failure behavior an agent needs to plan for.

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 short sentences, each earning its place: what it returns, why to call it first, and the failure-handling guarantee. The routing instruction is front-loaded.

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?

No output schema exists, so the description carries the return-shape burden, and it does: asset, decimals, share price, per-subgraph index progress, plus unreachable-subgraph reporting. For a zero-parameter discovery tool this is complete.

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 no parameters, so there is nothing for the description to disambiguate; the 4 baseline applies. The description correctly does not invent parameter guidance.

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?

States a specific verb and resource ('Enumerates every vault across the configured subgraphs') and immediately scopes what each entry carries. It is clearly distinguishable from siblings like vault_overview or compare_vaults, which operate on vaults already known from this 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?

Explicitly instructs 'Start here' and explains why: the addresses and source keys returned are the arguments the other tools consume. This is a concrete when-to-use rule that routes the agent to this tool before the siblings.

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