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

Annotations already indicate non-read-only and potentially destructive behavior; the description adds meaningful context beyond them: it uses only buyer-supplied information, performs no external actions, returns a draft for human review, costs 0.25 USD, and requires explicit wallet authorization. This gives an agent a good safety picture, though it does not detail the meaning of openWorldHint or destructiveHint.

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?

Four tightly written sentences cover function, constraints, output, price, and payment. The main verb and resource appear first, and every sentence adds 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?

The description is incomplete for a tool with five parameters, a nested input object, and no schema descriptions. It covers the overall service and output shape well, but an agent cannot confidently determine how to supply labels/definitions, what brief versus source_text means, or what the signature and expiry fields are for.

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 0%, so the description needed to explain the parameters, but it does not. The phrase 'labels and definitions' has no corresponding schema property, leaving it unclear whether they belong in input.brief. No explanation is given for source_text, audience, result_expires, idempotency_key, result_signature, or payment_signature.

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 uses a specific verb and resource: 'Classify supplied text using supplied labels and definitions.' It also names distinctive output features (rationale, uncertainty, unknown category), which sets it apart from sibling tools like sentiment_analysis or label_taxonomy.

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?

The description makes the use case clear: classify text when custom labels and definitions are supplied. It also gives a strong exclusion: 'no external research or outbound actions.' It does not explicitly name sibling alternatives, so it stops short of a 5.

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