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

With no annotations, the description carries the full burden. It discloses key behavioral details: endpoints are probed on a fixed clock, blocked/rate-limited are distinguished from unreachable, and readings are traceable to retained captures. It also mentions the output includes current observation plus 7 days of counts, but does not detail exact response format or any side effects.

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 somewhat verbose with marketing-like phrasing, but it front-loads the purpose and includes all essential details. It is not overly long and every sentence contributes useful context, though it could be tightened without losing 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?

For a tool with one parameter and no output schema, the description covers the purpose, when to use it, and key behavioral aspects. It explains what the tool returns (current observation plus 7 days of counts) and mentions the methodology. It lacks explicit response structure details, but given the simplicity, 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?

The single parameter endpoint_id has 100% schema description coverage, so the schema already explains it. The description does not add extra meaning about the parameter beyond what the schema provides, so the baseline score of 3 is appropriate.

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 function: providing current readings of x402 and MPP endpoints, including aliveness, quoting, and speed. It also differentiates from the sibling tool by specifying this is the 'FREE grade' with current observation plus 7 days of counts, making it distinct from the history tool.

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 advises calling this tool before paying an unfamiliar endpoint or checking for repricing/rotation of payTo. It implies the sibling is for history, but does not explicitly name the alternative or state when not to use it. The guidance is clear and actionable, though not exhaustive.

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