search_companies

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

No annotations are provided, so the description carries the full burden. It discloses case-insensitive matching, taxonomy and currency filter semantics, and the in_index=False edge case with tickers like 'AAPL', which is valuable behavioral detail beyond the 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?

The description is compact and well-structured, front-loading the primary action and then explaining filters. Every sentence earns its place, including the important edge-case note, with no wasted words.

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 8 parameters, no annotations, and an output schema that handles return values, the description covers the search behavior, key filters, and an edge case. It could briefly mention domicile/exchange semantics or screen_companies as an alternative, but overall it is largely sufficient for an agent to use the tool correctly.

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?

The description adds meaning for key parameters: query (substring/ticker prefix), taxonomy (us-gaap vs ifrs-full), currency (ISO-4217), and in_index (Russell membership and filtering behavior). However, tier, domicile, exchange, and limit are not explicitly described, though some are self-explanatory by name.

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 states 'Find US public companies by name substring or ticker prefix (case-insensitive)', clearly identifying the verb, resource, and scope. It also distinguishes itself from sibling tools like search_filings by defining its lookup purpose.

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 explicitly tells when to use this tool: 'Use this to look up a company before querying its financials, ratios, or filings.' It provides clear context but does not explicitly mention when not to use it or how it compares to screen_companies.

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