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

Annotations only indicate a non-read, non-destructive operation. The description adds substantial behavior: rejects unknown/expired contracts, requires verified OCC symbols for options, signed quantity semantics, positive costPerUnit, and idempotent retries within a duplicate window. This goes well beyond annotations and is critical for correct usage.

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 dense but each sentence adds unique value. It leads with purpose, then covers inference prohibition, instrument specifics, quantity/cost semantics, and idempotency in a logical order. No redundant or filler content; every sentence earns its place.

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 the tool's complexity (7 parameters, 5 required) and no output schema, the description covers all critical usage constraints: instrument selection, signed quantity, cost semantics, rejection rules, and duplicate behavior. It doesn't mention prerequisites like portfolio existence, but that's a minor gap likely handled elsewhere. Overall, it's quite complete for a write operation.

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 100% with detailed descriptions, so the baseline is 3. The description adds meaningful cross-parameter context: that for options you must pass both the underlying ticker and the optionContract, and that costPerUnit is never the per-contract total. These relationships are not explicit in the schema, elevating the score.

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 first sentence states a specific verb ('Record') and resource ('a user-confirmed purchase or sale in the caller's portfolio'). It clearly indicates this is a write operation for adding lots, distinguishing it from siblings like UpdatePortfolioLot, RemovePortfolioLot, and GetMyPortfolio. The purpose is unambiguous.

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 gives clear context for instrument types (stock vs option), requires user confirmation ('Never infer or guess'), and explains idempotency for retries. It does not explicitly name alternative tools, but the context and sibling names make it obvious that this is for adding new lots. The guidance is solid but could be strengthened by explicitly saying 'use this to add a new lot, not to modify or close an existing one.'

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