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

Annotations already establish readOnly, idempotent, non-destructive behavior, so the description doesn't need to restate safety. It does add real context beyond them: the exact field set returned (price, basis, funding, spread, open interest, 24h volume) and the caveat that fields appear only 'where the venue publishes them', warning of sparse/null values across venues.

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 sentences, front-loaded with venues and returned fields, then the filter. The field enumeration is dense but each item is informative; no 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 by naming every field an agent can expect. Combined with the partial-publishing caveat and full schema coverage for the single parameter, nothing needed to call it correctly is missing.

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% and the schema already documents the base filter with the same BTC/ETH/CC examples and the 'leave out for every market' default. The description restates rather than extends that, so it adds no meaning 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?

Names the resource precisely (perp markets) plus the three venues it covers and enumerates the data fields returned, so an agent knows exactly what it gets. It stops short of differentiating itself from sibling-looking tools such as premiums or spreads, which also sound like rate/spread data.

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 only implied: read perp market data, optionally narrowed by asset. There is no explicit when-to-use or when-not, and no pointer to premiums/spreads/market_overview as alternatives for overlapping price or spread lookups.

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