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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuinely useful behavioral context beyond them: the cost model ($0.003 USDC per successful call via x402 across Base/Solana/Arc) and that failed calls are not charged. Auth/payment requirements are surfaced, though rate limits or pagination behavior are not.

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?

Front-loads the core purpose, then what is returned, then the limit, then compliance/pricing notes. Slightly padded by the 'Information only, not financial advice' disclaimer, but every other sentence carries information and the ordering is sensible.

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 an output schema present, return values need not be detailed, and the description still summarizes the payload (question titles, action types, amounts, tx hashes). Combined with the payment disclosure, an agent has what it needs to call it correctly; only sibling differentiation 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?

Schema description coverage is 100%, so the schema already documents both the wallet address and the limit parameter. The description only restates 'Limit up to 100 items', adding no format or syntax detail beyond what the schema provides; baseline 3 applies.

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?

States a specific verb ('Fetches') and resource ('trading and on-chain lifecycle activity') scoped to a Polymarket user or proxy wallet, and enumerates the activity types (trades, splits, merges, redemptions). It is clear on its own, but it never distinguishes itself from close siblings like pm_trades or pm_history, which an agent must otherwise guess between.

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 implies the general context (retrieve activity for a wallet) but offers no when-to-use guidance, no exclusions, and no mention of the alternative activity tools (pm_trades, pm_history) that overlap heavily. Nothing tells the agent when this is the right pick versus a sibling.

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