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

The description adds meaningful behavioral context beyond the generic annotations: it states the holding is created empty ('no lots yet') and that a live-price source is picked from the kind unless explicitly given. It could say more about duplicate/conflict behavior, but the annotations already cover the basic safety profile and nothing is contradicted.

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 two sentences with the core purpose front-loaded. Every clause earns its place by either defining the tool's scope or routing to the correct alternative, with no filler or repetition.

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 present and several parameters already described in the input schema, the description is largely sufficient. Minor gaps remain around duplicate holdings and the optional account_id behavior, but these are secondary given the schema and sibling context.

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 50%, and the description adds only modest parameter-level insight: it enumerates kind values in prose and clarifies the quote_provider default behavior. It does not explain account_id, quote_symbol, or symbol beyond what the schema already provides, so it is adequate but not rich.

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 and resource: 'Create an investment holding' and immediately clarifies the object type (stock, ETF, mutual fund, gold, crypto). It also explicitly distinguishes itself from record_lot and import_holdings, so an agent can tell what this tool does versus those siblings.

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?

It directly says to use record_lot for buys/sells and import_holdings for broker exports, giving clear exclusions. 'With no lots yet' also frames the tool's role as initial holding creation, so the agent knows when it is and is not appropriate.

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