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

With no annotations provided, the description carries the full burden. It discloses the source (SEC EDGAR), annual default, quarterly opt-in, and filtering options, adding useful context beyond the schema. However, it does not mention return format, pagination, data coverage limitations, or read-only status, leaving some behavioral aspects undisclosed.

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, front-loaded with the core function, followed by a clear usage directive. Every clause adds value—source, scope, filtering, defaults, and when to invoke—without redundancy or fluff.

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?

The description covers the tool's purpose, source, data types, filters, and default behavior, which is solid given no output schema. However, it lacks details on return structure, coverage depth, or edge cases (e.g., what happens for tickers with sparse history), and no output schema exists to fill that gap. For a tool with 5 parameters and no annotations, this is workable but not fully complete.

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 only 20% (ticker's path description), so the description must compensate. It does: 'filterable by statement_type and start_year/end_year, annual by default with include_quarterly opt-in' explains what these parameters control and clarifies the default behavior. This adds meaningful semantic guidance beyond the raw schema, although ticker itself is not further described beyond being required.

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 provides 'multi-decade historical financial statements for one ticker from SEC EDGAR' covering income, balance, and cash-flow. It identifies the exact resource (financial statements), scope (one ticker, multi-decade), and source (SEC EDGAR), and distinguishes this from siblings by focusing on historical trends rather than the latest print.

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 gives explicit usage guidance: 'Call this when the user asks how fundamentals have trended over many years, not just the latest print.' This clarifies the intended use case and contrasts with alternative tools for recent data, though it does not name specific sibling tools or explicitly state when not to use it.

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