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

With no annotations, the description fully discloses behavior: returns endpoints, explains x402 payment (gasless, EIP-3009), and clarifies that MainStreet does not proxy or charge. This is comprehensive.

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 5-6 sentences, informative but slightly verbose. It front-loads the purpose and uses clear structure. Could be tighter, but still effective.

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?

Given a single optional parameter and no output schema, the description covers all necessary context: purpose, usage timing, behavioral details, and endpoints. Nothing important is missing.

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% (pattern and description), so baseline is 3. The description adds value by explaining the parameter as 'prefills a ready-to-call URL,' which clarifies its purpose beyond the schema.

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 that the tool provides the momentum layer (xsignal) for vetted tokens, returning specific endpoints. It distinguishes from siblings like mainstreet_onchain_info by contrasting safety vs. momentum.

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 explicitly says 'Use after a SAFE/WATCH verdict to decide whether to actually enter.' This provides clear when-to-use guidance. It lacks explicit when-not-to-use but implies it via xsignal's abstention behavior.

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