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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description adds real value beyond them: the shape of each row (display_label composition and the integer `id` field), the fact that the id maps to broker_account_id, and the explicit empty-result behavior. It stops short of describing pagination or ordering, but that is minor for a small list tool.

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, front-loaded with the scope statement, then output shape, then the safety caveat and empty-state fallback. The display_label format string is dense but it is genuine information rather than filler; nothing is redundant.

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?

An output schema exists, so the description is not obligated to explain return values at all, yet it still covers scope, row identity semantics, the no-invented-IDs safety rule, and the empty state. Nothing an agent needs to call this 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 tool takes zero parameters, so the baseline is 4. The description's discussion of row fields describes output rather than inputs, which does not conflict with the schema and adds no confusion.

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?

Specific verb+resource ('List all connected broker accounts and wallets') with an explicit scope qualifier ('not Alpaca-only') that prevents the agent from confusing this with the Alpaca-oriented trading tools in the sibling set. An agent can distinguish it from list_instances, list_my_algos, and list_pending_trades without opening any schema.

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?

Offers operational guidance ('Prefer paper/demo; never invent IDs') and an explicit empty-state fallback URL, which is more than most list tools provide. However, it never states when to reach for this versus another lookup tool, nor any prerequisites (e.g., whether a connection must exist first), so usage is only implied.

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