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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds valuable behavioral context: it enumerates the ~36 fields returned, notes that the result is per company, and mentions the report/fiscal/currency stamps. It does not describe pagination or limit behavior, but that is minor given the output schema and annotations. No contradiction with annotations.

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 two sentences with zero filler. The first sentence front-loads the return content (fields and structure), and the second sentence gives usage guidance. Every word adds value, and the structure is clean 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?

Given the tool has a well-defined output schema and 100% schema parameter coverage, the description covers the essential purpose, usage, and return content. It addresses the primary decision point (balance sheets vs. metrics) and notes the required period. There is nothing an agent needs to know to call it correctly that is missing; the schema and annotations fill the remaining gaps.

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 100%, so the baseline is 3. The description adds context about the return fields and usage but does not materially enhance parameter understanding beyond the schema. It restates that period is required (already in schema) and does not explain the enum values or the ticker/cik requirement (the schema handles those). Thus it meets the baseline but does not exceed it.

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 a clear verb+resource: it returns balance sheets for one company, and enumerates the key fields included. It distinguishes itself from the sibling get_financial_financial_metrics by explicitly noting that tool covers ratios computed from these numbers, and it also implicitly differentiates from income/cash flow statements by naming the financial statement type. An agent can immediately understand what this tool does.

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 it ('for capital structure and liquidity') and directs the agent to the alternative for ratios ('For the ratios already computed off these numbers use get_financial_financial_metrics'). It also states that period is required, which guides usage. This is clear, actionable guidance with a named sibling and exclusion condition.

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