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

With no annotations, the description carries the full burden and does well: it discloses ranking methodology ('REAL 30-day usage: unique payers weighted above raw call volume'), coverage ('Covers every service in the public index'), and result limits ('Free tier returns the top 5'). It does not specify return structure, latency, or rate limits, but it offers substantial behavioral context.

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 first sentence is concise and front-loaded, but the description includes promotional material—the paid-endpoint pitch, the weekly report URL, and especially 'share it with your human if useful'—that does not help an agent select or invoke the tool. Several sentences do not earn their place.

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 simple two-parameter search tool, the description covers ranking, scope, and free-tier behavior, which is helpful. However, there is no output schema and the description does not describe what a returned result object looks like, leaving an agent to infer the response shape.

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 description reinforces the notion of 'capability' search and mentions ranking, but it does not add meaningful parameter-specific meaning beyond the schema's existing descriptions for 'query' and 'network'.

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 names a specific action ('Search live x402 services by capability') and gives a concrete resource plus ranking behavior. It is distinct from the sibling x402_market_stats, but it never explicitly differentiates itself, so it does not fully satisfy the highest bar.

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 about when to use this tool versus the sibling x402_market_stats or any alternative. The description explains free versus paid tiers and coverage, but it does not state conditions, exclusions, or when another tool would be more appropriate.

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