Account snapshot

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

Annotations already declare readOnlyHint and openWorldHint, so the description does not need to restate safety. It adds valuable context by specifying the included fields and defining the trading day boundary (17:00 America/Chicago), which affects how realized P&L and the loss limit should be interpreted.

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 sentences with no filler: the first packs the full content list plus the timezone qualifier, and the second states the intended use. The most decision-relevant information 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?

For a single-parameter read-only snapshot, the description adequately covers inputs, output contents, and usage context. The lack of an output schema is mitigated by the explicit enumeration of the snapshot's components.

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 only parameter, accountId, already has a descriptive schema entry ('Trading account ID from list_accounts'), and schema description coverage is 100%. The description adds no extra parameter-level detail, so the baseline 3 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?

The description opens with 'One-call view of an account' and enumerates the exact contents: balance, open positions, working orders, today's realized P&L, and daily loss limit. This clearly distinguishes it from narrower siblings like list_open_positions or get_performance by emphasizing the composite snapshot nature.

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?

The closing instruction, 'Use this to monitor between decisions,' gives a clear usage context for a monitoring tool. It does not explicitly name alternatives or state when not to use it, but the intended context is unambiguous enough for an agent.

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