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

With no annotations, the description carries the full burden, and it does disclose the return contents well (fills plus buy/sell split, net flow, VWAP, largest print, average size). However it says nothing about auth/payment requirements, rate limits, record caps, or error behavior for a market-data call — gaps an agent would want covered given zero annotation support.

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 the core purpose, then the routing hint. The stat enumeration is dense but each item is informative rather than filler; slightly long, but nothing is wasted enough to drop below a 4.

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?

The description compensates for the missing output schema by describing the response shape, which is a real contribution. But against five undocumented parameters and no annotations, the definition leaves identification and windowing semantics unexplained, so it is only minimally 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?

Five parameters exist at 0% schema description coverage, and the description names none of them (id, symbol, instrument, hours, limit). 'Recent trade tape' only faintly implies a time window; the agent gets no guidance on how to identify the market or bound the result set.

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 — the recent trade tape for one Polymarket Perps market — and enumerates the exact payload (fills with side/price/size/timestamp plus derived flow stats). It distinguishes itself from x402-polyperp-book by name, so an agent can route without opening either 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?

Explicitly names the alternative (x402-polyperp-book) and the condition that selects this tool: 'this to see what actually executed.' No exclusion rules or prerequisite context for the time-window/limit behavior, and it omits other plausible siblings (polyperp-quotes, polyperp-candles), so it falls just short of a 5.

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