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

Annotations already provide readOnlyHint, so the tool is read-only. The description adds significant behavioral context: it's FREE, shows data age and cost, and batch mode requires a Bearer key. No contradiction with annotations. Could mention rate limits or authentication details, but the additions are valuable.

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?

Description is three sentences, front-loaded with 'FREE pre-flight', and each sentence adds essential information. No wasted words, and the important points (what it checks, how to use, when to call) are efficiently conveyed.

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?

Given that an output schema exists (from context), the description does not need to detail return values, and it mentions what the tool returns (coverage, data_age_days, cost). It covers single and batch usage but misses potential error conditions or the exact limit of 1000 addresses. Still, it is fairly complete for a pre-flight check tool.

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 only 25% (only addresses has a description). The description compensates by explaining the purpose of lat+lon, address, and addresses parameters, including the batch capacity up to 1000. It adds meaning beyond the bare schema, though details on required/non-required are not given.

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?

Description clearly states the tool checks coverage, data staleness, and cost for a US address/point. It distinguishes single vs batch mode and uses 'pre-flight' to indicate it should be called before spending. The specific verbs and resources are clear, and the tool's purpose is distinct from siblings like 'ask_inspector' or 'buy_credits'.

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?

Description explicitly says 'Call this before spending' and explains when to use single address vs batch mode. It implies the tool is free. It does not exclude alternatives or provide when-not guidance, but the context of siblings and the pre-flight nature make usage clear enough. A slight gap for not mentioning when not to use.

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