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

Annotations already cover safety (readOnlyHint) and world scope (openWorldHint), so the bar is lower. The description adds valuable negative scope — cross-venue candidates, profits and Kalshi data are unavailable via MCP — which tells the agent what to expect from results.

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?

Three short sentences, front-loaded with what is returned followed by exclusions and alternatives. The URL earns its place as the only route to human comparisons; 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?

An output schema exists, so return values need not be explained, and annotations carry the safety profile. The description covers scope, exclusions and an alternative path, leaving little an agent needs 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 description coverage is 100%, so both parameters (family, max_capital_usd) are already documented in the schema; baseline 3 applies. The description adds no additional semantics for either parameter.

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 concrete verb+resource ('Return independent Polymarket quotes and the website notice only') and explicitly separates itself from siblings by naming list_executable_opportunities. It is clear about actual behavior, though the mismatch with its own name ('arbitrage_candidates') adds some friction an agent must reconcile.

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 gives explicit routing ('Use list_executable_opportunities for Polymarket quotes') and an external human-comparison link. Guidance is present and actionable, but the redirection toward another tool for the same 'Polymarket quotes' purpose is mildly confusing rather than a clean when/when-not split.

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