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

Beyond the annotations, the description discloses substantial behavior: Serper/Google sourcing, top-result fetching, per-page ok/status and fetchedOk fields, the 12K character cap, billing only when results return, non-charging on zero results or provider errors, $0.03 pricing via x402 in USDC on Base, Base-only MCP payments, and a security warning that returned content is untrusted third-party data. This is unusually rich disclosure for a paid tool.

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 purpose and key constraints are front-loaded, and the pricing, billing, security, and terms details all earn their place for a paid API. It is still a dense single paragraph that could be more scannable, but it is not padded.

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 paid, open-world search tool with no output schema, the description is complete: it explains the return JSON shape, per-page success/failure fields, character limits, billing behavior, payment rail, and untrusted-content risk. An agent has enough information to call it and interpret partial failures correctly.

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 both parameters are already documented. The description restates q's 300-character limit and n's 1-5 range with default 3, but adds no meaning beyond the schema. A baseline 3 is appropriate when the schema does the heavy lifting.

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 states a specific verb and resource: 'Web search API with page contents: current results with sources as markdown.' It also names the underlying provider (Serper/Google) and clarifies that top results are fetched as markdown. However, it never explicitly distinguishes itself from siblings like fetch, extract, or market_search, so an agent must infer the boundary.

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 explicit when-to-use or when-not-to-use guidance, and no sibling alternatives are named. The agent can infer this is for web searches, but with nearby tools such as fetch, extract, market_search, and http, the description leaves routing entirely to inference.

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