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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context in the form of the default time window ('since Sep 1, 2026') and the fact that `by` triggers a breakdown, though most of the metric list is redundant with the output schema.

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?

Front-loaded with the core action and metric list, followed by the default window and the `by` behavior; there is little wasted text. The dense metric parenthetical is information-rich but slightly heavy for a single sentence.

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 an output schema explaining return values and annotations covering safety, the description is adequate for a read-only stats tool. It falls short on tool-selection context (why this over get_track_record) and does not clarify that it scopes to the caller's own account versus other traders.

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?

Schema coverage is high (86%), so the schema already documents most parameters, which sets the baseline at 3. The description adds marginal meaning by noting the default window and that `by` produces a breakdown, but gives no detail on the enum values (league/band/hold) or the deprecated `month` parameter.

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 ('grades') and resource ('your closed trades') and enumerates the metrics produced, so the agent knows exactly what it returns. It does not, however, distinguish itself from close siblings like get_track_record, get_leaderboard or get_trader, so the agent must infer the difference.

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?

There is no explicit statement of when to use this tool versus alternatives such as get_track_record or get_trader, and no prerequisites or exclusions are given. The only usage-ish note ('Default since Sep 1, 2026. by adds a breakdown.') concerns parameter behavior, not tool selection.

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