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

Annotations only cover the read-only/idempotent/open-world safety profile; the description goes well beyond them by disclosing the paid-call mechanic (x402 USDC on Base, $0.002 per successful call) and the exact behavior of an unpaid call. It also caps behavior at 20 results and enumerates the returned fields, which is meaningful context for a tool with no output schema.

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?

Purpose and workflow position are front-loaded in the first clause, followed by examples, return shape, and cost. Every sentence carries distinct information — routing, examples, output fields, billing — with no restatement of the title or name.

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 no output schema, the description carries the burden of describing returns and does so (match count, symbol, names, quote type enum, exchange, sector, industry). Combined with the cost/payment disclosure and routing guidance, an agent has everything needed to call this correctly and interpret the response.

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 baseline is 3. The description adds real value on top by showing the normalizations 'q' accepts (common name, index name, non-US ticker, crypto pair) and by clarifying the result ceiling that 'limit' operates within. It does not, however, explain the string-typed limit or default of 8 beyond what the schema says.

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 names a specific verb+resource (resolve a name to a tradable ticker) and immediately grounds it in concrete input→output examples ("apple" -> AAPL, "s&p 500" -> ^GSPC, "bitcoin" -> BTC-USD). It also names the downstream tools it feeds (/v1/quote, /v1/history), so an agent can place it in a workflow without opening the schema. Overlap with the crypto_search sibling is not addressed, but the stated return types and examples make the scope clear.

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?

It gives explicit sequencing guidance: use this to resolve a name "before calling /v1/quote or /v1/history," which routes the agent away from those siblings. It also tells the agent what happens if it calls without payment (a PaymentRequired object), which is a usage precondition spelled out rather than inferred.

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