lookup_issuer

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

The description adds value beyond annotations by explaining the return values (CIK, legal name, tickers, exchange) and the tool's role as a prerequisite for other tools. Annotations already declare readOnlyHint and openWorldHint, which are consistent with a read-only lookup.

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?

The description is succinct with three sentences, front-loading the purpose. Every sentence adds value, with no redundant or extraneous information.

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?

Given the tool's simplicity, existence of output schema, and annotations, the description is complete. It explains the query usage, output, and workflow integration. The limit parameter is not detailed, but it's 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 description coverage is 0%, so the description must compensate. It explains the query parameter (ticker or name part) but does not describe the limit parameter. This provides partial coverage for a simple tool, warranting a score of 3.

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 clearly states the tool resolves a company name or ticker to its SEC CIK and basic identity, using specific verbs and resources. It distinguishes from siblings list_filings and search_filings which operate on filings, not issuers.

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 description provides clear context: use this tool to obtain a CIK before using other tools. It gives examples of input (ticker or name part) and explains the output. It doesn't explicitly state when not to use it, but the purpose is well-defined and distinct from siblings.

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