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

With no annotations supplied, the description carries the full burden and does substantial work: it discloses cost (free), a concrete rate limit (100/day per wallet, keyed on the caller parameter), and that the response contains state disclosure but zero answer entries. It does not say what happens when the quota is exhausted or what the disclosure payload looks like, which keeps it below a 5.

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?

A single dense sentence front-loads the most decision-relevant fact (FREE), then quota, then the required caller argument, then scope, then the negative guarantee. Every clause carries information and nothing is padded.

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?

Cost, quota, required-argument behavior, and output absence are covered, which is a lot for a 4-parameter tool with no annotations. However, there is no output schema, so the description is the only source of return information and 'load-state / assessability disclosure' is left unexplained, leaving a real gap for an agent deciding what it will receive.

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 the schema already documents all four parameters, including that caller keys the free allowance. The description's mention of 'pass caller' and the wallet-based quota restates schema content rather than adding new meaning about legs, topic, or question_class.

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+resource: a pre-check that performs input validation and returns load-state/assessability disclosure. It also explicitly negates what it does not do ('No answer entries are produced'), which separates it from a lookup. It stops short of naming query_index_lookup as the paid counterpart, so the sibling differentiation is implied rather than explicit.

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 phrase 'before any payment' gives clear context for when to call it, and 'FREE' plus the 100/day quota tells the agent why to prefer it over a paid call first. There are no explicit exclusions or a named alternative tool, so it lands at clear-context-without-exclusions rather than full when/when-not guidance.

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