fetch_positions_history

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

With no annotations, the description carries the full burden and does reasonably well: it discloses the auth requirement ('Requires API credentials'), the exact return shape (`{ items, next_cursor }`), the pagination contract, and the fact that `limit` is per-page. It omits whether the call is read-only framed explicitly and any rate-limit or error behavior, keeping it out of the top band.

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?

Front-loaded with purpose, then return shape, then the pagination loop, then the parameter caveat. Four tight sentences, no filler, and the most error-prone point (`limit` is per-page) is called out explicitly.

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?

There is no output schema, so the description correctly compensates by documenting the response envelope and cursor semantics, and it fully covers the 2-parameter surface. The remaining gap is sibling disambiguation against `get_closed_positions`/`fetch_positions`, which an agent selecting a tool would still need.

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 already 100%, so the baseline is 3, but the description adds real meaning: it clarifies that `limit` sizes ONE page and is not a total, and that `cursor` must be the previous `next_cursor` verbatim. This reinforces and contextualizes the schema rather than merely 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 concrete verb and resource ('Get the authenticated account's closed positions') and clarifies the payload is realized PnL per position. However, the sibling list contains both `get_closed_positions` and `fetch_positions`, which appear near-duplicate, and the description offers no basis for choosing among them.

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 strong usage mechanics for pagination — keep passing the previous `next_cursor` and stop when it is null — but never says when to use this tool versus `get_closed_positions`/`fetch_positions`, nor any when-not condition. Usage is implied by the pagination walkthrough rather than by selection guidance.

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