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

Annotations only carry generic false hints; the description adds key behavioral context: the operation costs 0.01 USDC per query, is limited to 20 queries/session, and is the paid stage after a free preview. This goes beyond annotations, though it doesn't detail effects like balance deduction or error behavior.

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?

Three concise sentences front-load the value proposition and critical constraints (cost, max queries) before the sequence. Slightly sales-oriented, but all sentences carry useful information with no 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?

The paid nature, cost, and session sequence are covered, but the tool has 5 parameters, no output schema, and no parameter details for query/k/delivery_receipt. An agent cannot reliably construct a correct call knowing only that it is a paid query step.

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?

With only 40% schema description coverage and no param explanations in the tool description, essential parameters such as k, query, and delivery_receipt remain under-specified. The description focuses on pricing and sequence rather than meaning or format of the parameters, leaving the agent to guess.

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 identifies the tool as a paid per-query access to live data listings, with a concrete listing (quakewatch) and price, and anchors it in the sequence data_session_open → data_session_fund → data_session_query. It is distinguishable from the free data_preview sibling, though the verb 'Buy' is slightly indirect for a query-execution tool.

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?

Explicit timing and alternatives: 'first taste free via data_preview' and 'Sequence: data_session_open → data_session_fund → data_session_query' tell the agent to preview for free, open and fund a session, then use this tool. No ambiguity about when to call it.

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