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

Annotations already declare readOnly, idempotent, and openWorld, so safety is covered. The description adds substantial behavior beyond that: the match ordering (exact ticker first, then ticker prefix, then name words), the 25-result ceiling, the paid x402 USDC-on-Base pricing at $0.001 per successful call, and the critical detail that an unpaid call returns a PaymentRequired object rather than an error.

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?

It is a single, front-loaded sentence that leads with the usage condition, and every clause (matching order, result cap, payment model, PaymentRequired response) carries unique information. It is dense and long, but not 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?

For a two-parameter, no-output-schema tool, the description covers trigger, matching behavior, result volume, and the unusual payment handshake, which is what an agent needs to invoke it correctly. It stops short of naming the returned fields (ticker, CIK, company name), which the agent must infer, but that is a minor gap.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning about how the q parameter is interpreted — matching against SEC's official ticker list with exact-ticker prioritization before prefix and name-word matching. The limit cap is restated but the matching semantics are information the schema does not carry.

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 gives a specific verb and resource — searching SEC's official ticker list (NYSE, Nasdaq, OTC, CBOE; ~10,000 companies) to resolve a name or partial ticker to an exact ticker and CIK. It explicitly frames itself as the step preceding financials or filings lookups, which cleanly separates it from the sibling tools company, filings, and financials.

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?

Opens with a precise trigger: 'Use when you have a company name (or partial ticker) and need its exact ticker and SEC CIK before looking up financials or filings.' That states both the condition for using this tool and the follow-on tools, so the agent knows exactly when this is and isn't the right call.

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