Option trades

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive). The description adds genuinely useful behavior the annotations cannot express: large results are persisted rather than returned, and a result_id is handed back to be fetched via results_query. It omits pagination/truncation behavior details and rate limits.

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?

Two tightly packed sentences: the first gives resource, identifier scheme and units; the second gives windowing and the large-result/result_id behavior. Front-loaded and zero filler.

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 the return-value burden and does so partially, disclosing the unit conventions for premium and size plus the result_id escape hatch for oversized responses. It never describes the row shape (fields per trade) or truncation semantics, which leaves a small gap for a 6-parameter tool.

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%, so every parameter (start, end, lookback, sort, page_token, occ_symbols) is already documented in the schema, including the P1D default that the description repeats. The description adds units context ('premium per share in USD, size in contracts') but nothing about the inputs beyond the schema, so the baseline 3 applies.

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+resource ('Historical trades for option contracts'), and the word 'Historical' plus 'by OCC symbol' implicitly contrasts with siblings like options_latest_trades and options_bars. It stops short of naming an alternative explicitly, so an agent must infer the boundary from the adjective alone.

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?

Gives concrete usage mechanics (window by start/end or lookback, default P1D) and routes to a specific sibling ('query with results_query') for the stored-result case. It does not state when to prefer this over options_latest_trades or options_chain, so the when-not side is absent.

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