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

With no annotations, the description carries full behavioral burden and does so excellently. It discloses that returns are 'not executable quotes or arbitrage claims' and warns about verification steps, which is critical context for adequately interpreting results. It also implies results are approximations by using 'candidate equivalent events'.

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 tightly structured: purpose, return value, caveat, and parameter explanation each in one sentence, with no fluff. It front-loads the primary action and quickly conveys limitations, making it easy to scan.

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?

The tool is moderately complex (cross-platform comparison) and has an output schema, so return values are already specified. The description adds all necessary context: purpose, output nature, critical caveats, and query usage. There are no missing pieces that would prevent correct invocation or interpretation.

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?

The input schema provides only types and defaults (coverage 0%), so the description must add meaning. It does explain the 'query' parameter as filtering by keywords in the market question. However, it doesn't explicitly describe 'limit', though its meaning is trivially inferable from the schema. This partial compensation justifies a 4 rather than 3.

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 uses the specific verb 'Compare' and identifies resources 'Polymarket vs Kalshi' with a clear scope of 'candidate equivalent events'. It distinguishes itself from executable-quote tools by explicitly stating it returns research signals, not executable quotes. This clearly differentiates it from siblings like get_executable_quote.

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 explicitly states when to use the tool ('as a research signal') and when not to use it for investment decisions by warning to verify order-book depth, fees, fills, and resolution rules before deciding cheaper contracts. Though it doesn't name an alternative tool, it clearly implies 'get_executable_quote' exists, making usage guidance explicit.

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