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

Annotations already establish readOnlyHint=true, but the description adds valuable behavioral context: it requires authentication (OAuth), which is not captured in annotations. It also spells out the runtime data so the agent knows exactly what fields to expect, including effective values, corrections, hidden flags, per-exit P&L, and annotation types. The only minor gap is lacking explicit note about pagination or absence of side effects, but overall it exceeds the annotation baseline.

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?

The description is a bit long but each sentence serves a distinct function: the first defines the output, the second gives the invocation context, and the third covers auth. The information is front-loaded with the core payload, and the style is grammatically dense without being tautological. It could be slightly shortened without losing value, but the structure is logical and weaves all necessary cues together.

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?

Given there is no output schema, the description carries the burden of explaining the return payload, which it does thoroughly (fields listed, fills with effective values, hidden flags, P&L, annotations). It also covers the prerequisites (OAuth) and the environment in which the tool should be selected (after list tools, before annotating). There is nothing an agent would need to know that is absent for safe invocation.

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 input schema already documents both parameters at 100% coverage (according to context signals). The description adds meaningful instructions for the 'key' parameter: "Never construct one" and tells exactly where to obtain it (journal_list_trades, journal_get_day, journal_search_notes, journal_add_trade). This is a practical guardrail beyond the schema. The context parameter's purpose is described but the description doesn't need to repeat schema content; the added guardrail earns a score above the baseline 3.

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 clearly states the resource and action: "One trade in full" with a specific verb (get) and the resource (a single journal trade). It enumerates what is included (summary fields, fills, P&L, annotations), distinguishing it from list-level tools like journal_list_trades and journal_get_day. No ambiguity about what this tool returns.

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 description explicitly states when to use this tool: "After journal_list_trades or journal_get_day when the user asks about a specific trade or before annotating it." This provides a clear contextual trigger and a concrete alternative-avoidance guide. It also mentions the prerequisite of a LuxAlgo account (OAuth), which is an additional usage condition.

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