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

With no annotations supplied, the description carries the full burden and does well: it discloses the cost ($0.05 USDC), accepted payment chains (Base or Solana), that no account or API key is required, and critically that failed calls are not charged — a billing-retry signal an agent could not otherwise know. It omits rate limits and response shape, which keeps it from a 5.

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-loaded with 'Paid.' so cost is the first thing the agent sees, then purpose, then price and payment rails. Every sentence carries distinct information with no repetition. The telegraphic fragments are terse rather than confusing.

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?

For a zero-parameter, no-output-schema price lookup, the description covers what is returned (USD price, 24h change, market-cap rank), what it costs, how to pay, and the failure-billing policy. Only the response format and any rate or freshness guarantees are missing, which are minor for this tool's complexity.

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 tool takes zero parameters, so the baseline is 4 and there is nothing further the description could clarify about inputs. The endpoint URL is a useful addition but is not parameter guidance.

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 and payload: 'Bless (BLESS) price: live USD price, 24h change and market-cap rank.' That is far more than the name alone conveys. It does not, however, tell the agent how it differs from the near-identical buy_coin_* or buy_crypto_price siblings, so the agent must infer that buy_tok_BLESS is the BLESS-specific endpoint.

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?

Usage context is implied (fetch BLESS price) and the payment terms establish that this is a paid call costing $0.05 USDC on Base or Solana. But there is no explicit when-to-use-when-not guidance, no routing to buy_crypto_price for arbitrary assets, and no statement about whether repeated calls are needed or cached.

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