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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine value beyond that by disclosing a hard data-availability limitation (no Kalshi prices or derived spreads) and pointing to an external human-readable comparison page. It does not discuss pagination or freshness of the odds.

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?

Four short sentences, front-loaded with the return value, then the limitation, then the URL, then the alternative. Every sentence carries distinct information, though the link sentence lightly restates the 'link to human venue comparisons' already promised in sentence one.

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 annotations, full schema coverage, and an output schema in place, the description fills the remaining gaps: data scope, what is unavailable, and where to go for the adjacent need. Nothing an agent needs to select or call this tool 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?

Both parameters are fully documented in the schema (100% coverage), so the schema carries the load. The description adds nothing about limit or query semantics, so the baseline of 3 for high schema coverage is appropriate.

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: it returns independent Polymarket odds plus a link to human venue comparisons. It also pre-empts the mismatch implied by the name 'compare_platforms' by clarifying that no Kalshi-side comparison data is returned. It stops short of a clean one-line scope statement, but an agent can still tell what it gets.

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?

It explicitly states what this tool does not cover ('Kalshi prices and derived spreads are not available via API or MCP') and routes the agent to a named alternative for a related need ('For Polymarket order-book quotes use list_executable_opportunities'). It does not distinguish itself from other odds-adjacent siblings like get_market_odds or find_best_price, so it is strong but not complete.

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