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

Annotations only mark it read-only and open-world; the description adds crucial behavior: $0.02 USDC on Solana via x402 after quota, one free live GET per client per UTC day with specific headers, bare GET returning 402, and that this MCP tool returns payment requirements plus an HTTP URL rather than the pulse itself. These are exactly the payment, quota, and return-behavior details an agent needs.

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?

It is front-loaded with the live/full/payment distinction and then supplies quota, header, 402, return, and alternative information in compact sentences. The density is justified, though some HTTP-discovery wording is more operational detail than most agents need.

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 one-optional-parameter tool with no output schema, the description covers pricing, quota, headers, return type, and the free-preview alternative. It could be more explicit about the structure of the returned payment requirements and URL, but it is otherwise complete enough.

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 the single optional asset parameter is already documented in the schema as requesting a single-asset HTTP URL instead of the full pulse. The description does not add further parameter meaning beyond that baseline.

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?

It names the resource (live full market pulse) and states exactly what the MCP call returns: payment requirements plus an HTTP URL. It also explicitly contrasts this with get_market_sample as a free stale preview, so an agent can distinguish it from sibling tools without opening schemas.

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?

It identifies the free/stale alternative (get_market_sample) and explains the paid and free-quota conditions, including the headers needed for a free live GET. It does not spell out an explicit when-not beyond that preview alternative, but the choice between live paid and free stale data is clear.

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