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

Annotations already cover safety (readOnly, idempotent, openWorld, non-destructive), and the description adds real behavioral detail beyond them: the two-tier search order, the exact result fields (URL, USD price, networks, paying wallets, 30-day calls), and the TOLLA Pass eligibility rule tied to Robinhood Chain. It omits pagination/limit behavior and what an empty result set looks like.

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 dense sentences: the search scope and source order come first, then the return payload, then the empty-query rule. No filler, and each clause carries distinct information.

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?

No output schema exists, so the description rightly enumerates return fields and the pass-eligibility caveat. Remaining gaps are small: the limit parameter and result-count behavior are unexplained, but nothing critical to invoking it correctly 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 50%: query is documented in-schema, limit is not. The description compensates for query by defining the empty-string case as most-paid lanes, but says nothing about what limit controls or how it interacts with the two indexes, leaving the undocumented parameter unexplained.

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 paid x402 APIs (lanes) by keyword") and explains the two-source lookup order: TOLLA booths first, then the public x402 Bazaar index. It never names siblings such as list_booths or x402_market_scan, so an agent must infer the boundary with those tools rather than being told.

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?

"Leave query empty for the most-paid lanes" gives a concrete usage rule for the zero-argument case, which is the main ambiguity for a 0-required-param tool. There is no explicit when-not guidance or named alternative for keyword searches that should hit only one index.

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