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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description does not contradict them — the enumerated issuer universe is consistent with a closed-world read. It adds genuinely non-annotated behavior: the $0.005 USDC cost and the payment requirement, which is decision-critical for an agent. It stops short of disclosing data freshness/update cadence or whether partial coverage occurs for tokens lacking DEX or oracle prices.

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?

Two compact sentences, with the paid cost front-loaded so an agent sees the billing implication first. The field enumeration is dense but each item maps to a real return field; nothing is 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?

With no output schema, the description usefully enumerates the return fields and specifies the issuer/chain universe, which is what an agent needs to judge relevance. Remaining gaps are freshness/update frequency and whether the premium output is a superset of the free endpoint's — minor for a read-only data lookup whose payment path is covered by the api_key schema.

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 coverage is 80%, with chain, issuer, ticker, and api_key already documented including allowed values, so the schema carries most of the burden. The description's 'Filters ticker, chain, issuer, limit' merely restates the parameter names without adding semantics such as matching behavior, case sensitivity, or default limit. 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 resource (tokenized stocks) with explicit coverage: Ondo on Ethereum/BNB Chain and xStocks on Solana, plus the exact fields returned (contract, underlying ticker, supply, supply value, DEX vs oracle price, premium %). The 'PAID $0.005 USDC' prefix implicitly separates it from the free_tokenized_stocks sibling, but it never names that sibling or states the relationship outright.

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 lists available filters but gives no guidance on when to choose this paid endpoint over free_tokenized_stocks or free_tokenized_real_estate, and no exclusions or prerequisites. An agent must infer from the price marker alone that this is the premium variant.

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