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 the data source (Coinbase CDP Bazaar), payment rails (USDC on Base and other chains), and a non-obvious behavioral rule — results are 'ranked by relevance then cheapest first.' It omits pagination/default-limit behavior and what fields a result carries, but the ranking and pricing semantics are genuinely useful beyond the schema.

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?

Two front-loaded sentences: identity/scale first, then use case and filtering/ranking. Every clause earns its place — provenance, payment rails, cost preview, and ranking order — with no filler.

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 6-parameter, zero-required search tool with no output schema and no annotations, the description covers purpose, data provenance, filtering dimensions, cost preview, and result ordering. It could say more about default limit behavior and result fields, but nothing essential for a correct call 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 description coverage is 83%, so the schema already documents each parameter, including the subtle max_price exclusion rule. The description only restates the filter dimensions (chain, method, host, max price) without adding format, default, or interaction semantics, so it sits at the baseline for a well-documented 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?

States a specific verb and resource ('Search 17,863 x402-payable HTTP endpoints') plus scope (normalized from the Coinbase CDP Bazaar), which distinguishes it from siblings like search_mcp_servers and search_products. An agent immediately knows this searches a catalog of per-call payable APIs, not MCP servers or generic products.

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?

Gives a clear when-to-use: 'Use this to find an API an agent can pay for per call ... and to see what it costs before calling it.' It stops short of naming alternatives or exclusions (e.g., when to prefer search_mcp_servers), so it is strong context without routing guidance.

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