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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description adds value by specifying that Polymarket rows are wallet-attributed while Kalshi rows are anonymized, and that results are ordered newest first. It also states 'No API key required.' This goes beyond the annotations without contradicting them.

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 3-4 sentences, each providing essential information without redundancy. It front-loads the core purpose and efficiently adds behavioral details and disclaimers. No wasted words.

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?

Given a single optional parameter, no required params, an existing output schema, and thorough annotations, the description covers everything needed: data content, ordering, venue attribution differences, and authentication requirements. It is fully sufficient for an agent to select and invoke this tool correctly.

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 sole parameter 'limit' is fully covered by the input schema (type, min, max, description). The description does not add further semantics beyond what the schema provides. With 100% schema coverage, a baseline of 3 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 clearly states it returns 'latest large prediction-market trades' with specific fields (side, outcome, USD value, etc.) and distinguishes by venue (Polymarket vs Kalshi). This differentiates it from sibling tools like pm_data_calibration or pm_data_overview, making the purpose unmistakable.

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 notes it's a 'free public tape' with 'no API key required,' giving context on when to use it. However, it does not explicitly state when not to use it or mention alternatives among siblings, though the name and content make the use case clear. A slight gap in explicit exclusions prevents a perfect score.

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