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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds real value beyond them by disclosing the real-time broker round-trip and its latency ('may take a few seconds'), which an agent needs before calling it in a hot path.

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 distinct work: what it returns, the latency trait, and when to use it. The returned-field enumeration is front-loaded and nothing is padded.

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 output schema, the description carries the return-value burden and does so by naming the fields. It also covers latency and usage. Minor gap: no mention of failure modes such as an invalid accountId or an unreachable broker for a live-connection tool.

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?

Only one parameter, and the schema already documents it at 100% coverage, including its provenance ('from get_broker_accounts'). The description adds no further parameter meaning, so the baseline 3 for schema-covered parameters applies.

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 (get the current trading state of a broker account) and enumerates the exact fields returned: balance, equity, free margin, used margin, leverage, currency. That enumeration implicitly separates it from the list-style sibling get_broker_accounts, though it does not explicitly distinguish itself from get_account_info.

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?

Gives clear when-to-use context: 'check available margin before placing trades or to monitor account health.' This is a genuine workflow cue tied to sibling tools like execute_trade. It stops short of naming those siblings or stating exclusions, so it is not a full 5.

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