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 that it is 'Free, no key' and 'live', which are useful operational details. It does not mention rate limits or pagination, but given the read-only nature, the added context is sufficient. No contradiction with annotations.

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?

The description is a single sentence that front-loads the core purpose and lists the data fields, followed by a sentence about the optional parameter and a final sentence with example queries. It is longer than some, but every clause adds information (fields, usage, cost). The structure is logical: what → optionality → when to use. Slightly verbose but not wasteful.

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 must convey what the tool returns. It lists the exact data fields (price, 24h volume, open interest, max leverage, funding cadence, funding cost since launch) and explains the annualized metric. It also covers the asset filter and the free/no-key access. For a list-style tool with two optional parameters, this is complete. It doesn't describe pagination or default limit behavior beyond the schema, but that's minor.

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% for both parameters, so the baseline is 3. The description adds value by giving concrete examples for asset ('btc', 'gold', 'silver', 'ETH') and clarifying that it accepts 'symbol or name'. It also implies the optionality of asset by saying 'Pass asset for one perp', which clarifies the default behavior (all perps). This goes beyond the schema's minimal description.

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 clearly states the tool returns every Kalshi perpetual future with specific data fields (price, volume, open interest, leverage, funding). It distinguishes itself by explicitly naming the scope and the optional asset parameter, making it clear this is a board for perps, not a single-item tool. The verb is implicit but the resource and function are unambiguous.

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?

The description provides explicit example queries ('Kalshi perps funding rate', 'how much leverage on Kalshi gold perps', etc.) that directly tell an agent when to invoke this tool. It also notes it's free and requires no key, which clarifies access conditions. While it doesn't name alternatives, the examples and scope make the intended use cases very clear.

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