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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuinely new context: a concrete price ($0.0058 production USDC via x402 on Base mainnet), the fact the follow-up filing lookup is a separate paid request, and a data-coverage caveat. It does not explain what 'bounded' means numerically (the 20 cap lives only in the schema) or any pagination 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 front-loaded sentences: capability and scope first, then the follow-up workflow, then the caveat and price. Nearly every clause earns its place, though the embedded pricing/network detail and the example payload make the last portion feel slightly packed together.

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, return values need not be explained, and the description covers the remaining essentials: what is searchable, the downstream workflow to get_sec_filings, coverage limits, and payment cost. For a two-parameter paid lookup tool this is close to complete, missing only explicit limit-range guidance.

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 0%, so the description must carry parameter meaning, and it does: it tells the agent that 'query' accepts issuer name, ticker, or CIK, which the schema's bare string type does not. The example arguments {"query":"Apple","limit":10} also demonstrate the interaction of both parameters. It leaves the limit bounds (1-20, default 10) unstated, so it does not fully compensate for the coverage gap.

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 ('Search') plus a precisely scoped resource ('the official SEC company ticker reference data') and names the searchable fields (issuer name, ticker, CIK) and result shape ('bounded normalized candidates'). It implicitly separates itself from the generic search_company sibling by emphasizing the SEC ticker reference list, but it never names that sibling to make the distinction 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?

It states a concrete when-to-use scenario: when a CIK is unknown, pick a matching candidate and pass its cik to get_sec_filings in a separate paid request. It also warns the reference list is not a complete registry of every U.S. legal entity, which prevents over-trusting results. There is no explicit exclusion against the generic search_company alternative, so it falls short of a full 5.

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