Stock trades

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), yet the description adds substantive behavior: canceled/incorrect trades are dropped and counted in notes, and large results are stored rather than returned with a result_id. These are non-obvious traits an agent could not derive from 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?

Three tightly packed sentences with no filler; the core resource, the data-hygiene caveat, the windowing rule, and the large-result workflow are all front-loaded in that order.

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 no output schema, the description carries return-shape duty and does explain the result_id handoff and notes for dropped trades. It stops short of describing row fields beyond price/size, but for a paginated market-data tool this is nearly complete.

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%, so parameters are documented, but the description still adds value by clarifying units ('price USD, size shares') and the windowing model (start/end vs lookback with default PT20M). This meaningfully augments the schema rather than repeating it.

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?

States a specific verb and resource ('Historical trades for US stocks') with clear scope, and the 'historical' qualifier implicitly separates it from market_latest_trades and crypto_trades/options_trades siblings. An agent can identify the resource and asset class without opening the schema.

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 explains how to window data (start/end or lookback, default PT20M) and routes large results to results_query, which is useful context. However, it never names an alternative tool or states a when-not condition (e.g. use market_latest_trades for the current snapshot), so tool selection is left to inference.

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