Largest open perp positions in a market

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

Annotations only declare readOnlyHint and openWorldHint, so the description usefully adds that the snapshot carries snapshotIso/snapshotAgeSeconds, that marketSummary is whole-market and unfiltered with OI = long + short notional, and that filteredSideSummary covers only the filtered rows. This is real disclosure of return semantics; it stops short of stating permissions, rate limits, or pagination/refresh behavior.

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?

A single dense, front-loaded sentence that leads with what the tool is ('Perp snapshot drill-down') before enumerating return fields and summary semantics. It is a long run-on, but every clause carries information and nothing is padded.

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 18 parameters, no output schema, and only readOnly/openWorld annotations, the description does the heavy lifting: it enumerates returned fields, explains both summary blocks and the OI definition, and covers market resolution. Pagination and sort defaults are left to the schema, which is acceptable, but a note on output size or refresh cadence would round it out.

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 the baseline is 3, but the description adds genuine semantics the schema lacks: market matching is case-insensitive and a bare 'TSLA' resolves to 'xyz:TSLA' when unique, plus the meaning of the `filter` scope in filteredSideSummary. That resolves the practical ambiguity around the one required parameter.

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 states a specific resource and scope: 'open positions in one market, largest first', framed as a 'perp snapshot drill-down'. That is enough for an agent to know exactly what it returns, though it never names the adjacent siblings (flowscan_perp_markets, flowscan_address_perp_positions) to make the market-scoped vs address-scoped distinction explicit.

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?

Usage is implied by 'drill-down' and 'one market', suggesting it follows a market-level tool, but there is no explicit when-to-use, when-not, or named alternative. An agent must infer that this is the per-market position list and not the per-address list.

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