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

Annotations already cover read-only, idempotent, non-destructive and open-world. The description adds genuinely non-obvious behavior: the depeg alert fires above 50 bps, results are timestamped, the source is keyless DefiLlama, and each call costs 0.01 USDC via x402 on Base. The cost/payment disclosure is exactly the kind of context annotations cannot express.

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?

One dense sentence with no filler, and the operational facts (source, cost, alert threshold) are packed efficiently. Slightly penalized for the leading 'SYNTHORA stablecoin-supply:' label, which restates the name/title rather than adding meaning.

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 carries the return-value burden and does list the returned fields (supply, price, bps deviation, depeg flag) plus cost and source. It stops short of describing granularity or pagination, but for a single-parameter read tool it is sufficiently complete.

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 100% and documents the single 'input' string with an example, so the baseline is 3. The description goes further by clarifying that the parameter is an optional symbol filter, which the terse schema description does not make explicit.

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+resource (stablecoin circulating supply, price, peg deviation) and enumerates the entities covered (USDT, USDC, DAI). An agent can cleanly separate this from siblings like top_crypto, exchange_rates_verified, or defi_llama_tvl_ranking.

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?

Content implies usage (stablecoin supply/peg monitoring) and mentions an optional symbol filter, but never states when to choose this over sibling tools such as top_crypto or exchange_rates_verified, nor any exclusions or prerequisites for the paid endpoint.

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