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

Beyond the readOnly/openWorld annotations, the description discloses real behavioral traits: each quote is verified against the text and dropped if absent, answerable=false signals an unanswerable input, output is model-generated and should be verified, and pricing is per successful call with no charge on failure. These are exactly the quirks an agent needs.

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?

Dense, front-loaded, and every sentence earns its place: core behavior first, then quote-verification semantics, then the answerable flag, then the verification caveat and cost. No filler or redundancy.

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?

With an output schema present, the description need not explain return fields, and it still covers scope, validation behavior, the answerable signal, trust caveat, and billing. Nothing material for a correct call 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 description coverage is 100%, so both parameters are already documented, and the description only restates the 30,000-character text limit. It adds no meaning beyond the schema, so the baseline 3 applies.

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 ('Answers a question from the given text only'), and the scope constraint 'from the given text only' cleanly separates it from open-ended siblings like chat, text_faq, or summarize. An agent can tell what this does without opening the 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?

Usage is implied by the scope ('from the given text only'), but no alternatives are named and no explicit when-to-use/when-not guidance is offered. It does not, for example, route the agent away from chat or text_faq when the answer must be grounded in a provided passage.

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