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

The annotations already declare readOnlyHint=true and idempotentHint=true. The description adds important behavioral context beyond annotations: it is a signed x402 call, costs 0.03 USDC on Base, and provides real-time external data. This usefully signals payment/auth requirements and live external dependency.

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?

The description is extremely concise: three short sentences, each carrying distinct information—purpose, signing requirement, and cost. There is no redundant wording and the main action is front-loaded.

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?

The description covers purpose, cost, and signing, and annotations plus output schema cover safety and return shape. However, it lacks usage-selection guidance and provides no detail about what the input string should contain or how the sentiment signal is computed, leaving some ambiguity for the agent when preparing a call.

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 baseline is 3. The only parameter 'input' is described as 'parametros del producto (JSON o texto)', which is vague, but the description text adds no further parameter meaning. Schema does the heavy lifting, and the description does not clarify expected input structure.

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?

The description clearly states the tool's action and resource: 'Get real-time market sentiment signals via x402 M2M API.' This is specific enough to identify the tool's purpose. It does not explicitly distinguish it from sibling tools, though the sentiment focus is fairly unique among the listed siblings.

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?

There is no guidance on when to use this tool versus alternatives, nor any exclusions or context for selection. The description only says what the tool does, not when an agent should choose it over siblings like daily_intel_brief or macro_surprise.

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