Perp positioning snapshot per market

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds genuinely non-obvious context the annotations cannot carry: a refresh cadence ('every few minutes'), snapshotIso/snapshotAgeSeconds freshness fields, and the crucial definition that openInterest is two-sided (2x the one-sided figure some UIs show). It does not mention auth requirements or rate limits, which keeps it short of a 5.

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 sentences, front-loaded with what the tool returns; the OI-definition caveat and the sibling routing sentence each earn their place. Slightly dense in the first sentence's field enumeration, but no wasted text.

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 carries the return-value burden and does so by naming the key fields (long/short counts and notional, ratios, OI, avg entry, median leverage, unique addresses, snapshot timestamps). Combined with the routing guidance and the OI semantics note, an agent has everything needed to call and interpret this correctly.

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% (limit, fields, market, offset, sortBy all documented with defaults like 'openInterest desc'), so the baseline is 3. The description hints at the market-filter use case via the HIP-3 symbol example but adds no syntax or format detail beyond the schema.

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 ('Homepage perp snapshot for every perp market') and quantifies scope (~330 markets, including HIP-3 symbols like 'xyz:TSLA'). It explicitly distinguishes itself from siblings flowscan_perp_positions and the hip3_* tools, so an agent can select it without opening any 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?

Gives an explicit preference rule ('Prefer this for live OI/positioning') and names the alternatives with their distinct domains: hip3_markets/hip3_dex for HIP-3 history, hip3_binance_comparison for the Binance side. Both when-to-use and when-to-look-elsewhere are covered.

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