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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the DepthFeed exclusivity of full yes/no depth, that every account plan can access it, and the concrete failure mode that 'the keyless demo surface returns a 402 upsell.' This equips an agent to anticipate access-gated errors.

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 short sentences, with the core purpose front-loaded in the first clause. The access/failure context earns its place: it tells the agent who can use the tool and what error to expect in the keyless demo. No filler or repetition of schema content.

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?

For a moderate-complexity list tool with 100% schema coverage and readOnly/openWorld annotations, the description covers the essential external context (account plans, 402 upsell, DepthFeed scoping). Without an output schema, the response shape is not spelled out, but the cursor parameter references pagination.next_cursor, giving a usable pointer to the response format.

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%, with each of the four parameters documented (coin enum, type filter, limit range, opaque cursor). The description itself adds no parameter-level detail, but with the schema carrying the full burden, the baseline score of 3 applies; no compensation is needed.

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 verb and resource ('List Kalshi crypto markets') and adds the scoping qualifiers 'full yes/no depth, DepthFeed-exclusive,' which set it apart from the sibling search tools for other venues (limitless_search_markets, polymarket_search_markets) and from Kalshi data-retrieval siblings (candles, orderbook, snapshots). An agent can tell what this tool is for without opening the 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?

Usage context is implied rather than explicit: naming 'Kalshi crypto markets' signals this is the market-listing tool for Kalshi, and 'DepthFeed-exclusive' hints it is the surface for full depth. However, the description never names a sibling alternative or states when to prefer this over kalshi_get_candles/orderbook/snapshots, so the guidance remains implicit.

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