Get Company Facts Summary

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety and side effects. The description adds behavioral context by stating it returns a compact index with specific fields and explicitly says 'NOT the full time series,' which is a crucial limitation beyond the annotations. It could mention pagination or rate limits, but what it discloses is valuable and goes beyond the structured fields.

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 just two sentences, front-loaded with the core function, then the return contents, a key clarification, and usage direction. Every sentence earns its place with no redundancy or clutter. It is highly scannable and efficient.

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 simple discovery tool with two well-documented parameters and rich annotations, the description is complete. It explains what the tool returns, what it does NOT return, and how to proceed for more detail. The absence of an output schema is compensated by a clear description of the return shape. No critical information is missing.

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%, as both 'cik' and 'limit' have descriptions. The description does not add new meaning to the parameters beyond what the schema already provides. The 'compact index' phrase implies the limit parameter, but the schema already explains 'Max concepts to return.' Thus the baseline of 3 applies.

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 uses a specific verb ('Get') with a clear resource ('compact index of all available XBRL financial data for a company'). It explicitly states the output scope (concept names, latest values, data point counts) and distinguishes itself from sibling get_financial_metric by noting it is NOT the full time series. This fully clarifies the tool's 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 provides explicit usage guidance: 'Use this to discover what data is available, then use get_financial_metric for details.' This names a specific alternative and spells out the intended workflow, which is exactly the kind of when-to-use-versus-alternative signal expected.

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