create_lot

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

Annotations declare readOnlyHint=false (write operation), idempotentHint=false, destructiveHint=false. The description adds meaningful behavioral context: it is 'additive' with 'nothing else in the book changes,' the lot auto-closes when splits net to zero shares, and it errors if the account ref matches nothing. This goes beyond the binary hints, explaining side-effect scope and failure conditions. It doesn't contradict annotations.

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 well-structured: opening purpose, then usage flow, then an exclusion note, then an Args block. Every sentence contributes new information—no fluff. It's longer than minimal but appropriate for a tool with a non-obvious workflow and parameter formats. The front-loaded purpose and quick usage clarity earn it a 4; it loses a point for slightly dense formatting in the middle section.

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?

The description covers everything an agent needs: what the lot is for, the full lifecycle, how to chain it with sibling tools, parameter formats, error behavior, and when to skip it. An output schema exists, so return values need no description. For a 3-parameter tool with a defined workflow, this is complete and leaves no critical gaps.

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 0%, so the description bears full responsibility for parameter meaning. It explains each parameter: account accepts full path, %short GUID, or full GUID; title is a lot identifier with an example; notes are optional. This is far more than the bare schema (type: string) provides. The description fully compensates for the schema's silence.

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 uses a specific verb-resource pair ('Create a new, empty lot') and clearly states the purpose ('for cost basis tracking'). It distinguishes this tool from siblings by naming the exact flow (create_lot → create_transactions → assign_split_to_lot → calculate_lot_gain) and contrasting it with valuation-only tools (get_book_summary, balance_sheet). No ambiguity about what it does or when it applies.

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?

Provides explicit 'when to use' via the full workflow and states a clear exclusion: 'Skip this tool when you only want a valuation — get_book_summary and balance_sheet price holdings without lots.' It also names the specific alternative tools, leaving no inference burden on the agent. This is textbook usage guidance.

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