txpeek: check an address before a transaction

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

Annotations already establish the safe read-only, idempotent profile, and the description goes well beyond them: USD 0.005 pricing, free-tier quota (3 scans / 30 checks per IP per UTC day), p95 ~1 s and max ~4 s latency, 10-minute result caching, and the failure semantics ('if the chain cannot be read the call fails and is not charged'). The heuristic limitations and specific risk signals detected are unusual, valuable disclosure.

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?

Front-loaded with purpose, then routing, then returns, then cost/limits/limitations in a logical order. It is long and packs in a pricing figure and docs URL that are useful but not strictly needed for invocation, keeping it just short of a clean 5.

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?

Even though an output schema exists, the description summarizes the return shape (verdict enum, risk_score 0-100, plain-language reasons) with concrete examples. Combined with cost, latency, caching, and failure behavior, an agent has everything needed to decide whether and how to call it.

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 100% with a documented enum on chain, so the schema already carries both parameters. The description restates the supported chains and the address's role but adds no syntax or format detail beyond the schema, so the baseline 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?

States a specific verb and resource ('check an address for risk') and pins the exact moment of use ('right before you send a transaction to it, approve it, or buy its token'). It explicitly names two siblings it is not (scan_contract_address, check_token_honeypot), so an agent can route without opening either schema.

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 explicit when-to-use triggers plus named alternatives with the condition that selects each: full verified-source scan goes to scan_contract_address, sellability goes to check_token_honeypot. It also states the scope limits ('Heuristic, not an audit', 'a low verdict is not a clearance'), which is exclusions-level guidance.

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