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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: the exact return composition (bucketed realized P&L plus a live unrealized endpoint and max drawdown) and the API-key requirement.

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?

A single front-loaded sentence delivers the resource first and the return contents second, with no filler. The compound colon-list is dense but every clause carries information.

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 read-only tool with no output schema, the description compensates by spelling out what the curve contains. Parameters are handled by the schema and the auth prerequisite is stated, leaving little an agent needs that 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?

Schema description coverage is 100%, with both days (1-90, default 30) and step_min (5-1440) fully documented, so the baseline is 3. The phrase 'per bucket' loosely ties to step_min but adds no syntax or default information beyond the schema.

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 states a specific resource and enumerates its composition (starting balance, realized P&L per bucket, live unrealized point, max drawdown), so an agent knows exactly what comes back. It doesn't explicitly contrast itself with siblings like paper_balance or paper_report, which are the nearest neighbors.

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?

Usage is only implied: 'equity curve ... per bucket' suggests a time-series view as opposed to a point-in-time snapshot from paper_balance. The one explicit guideline, 'Requires an API key,' is a prerequisite rather than a when-to-use rule, and no alternative or exclusion is named.

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