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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds real behavioral context beyond that: results are computed only from matching verified SEC measurement periods, mismatched or unknown periods are propagated as unknown, and source inputs plus dates are retained — telling the agent how missing data is handled and that provenance comes back.

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?

Three sentences, front-loaded with the core purpose before the enumerated ratios and the exclusion list. The middle ratio inventory is dense but functional; nothing is redundant or padded.

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?

No output schema exists, so the description carries the return-value burden and does so by enumerating the ratio set and noting that source inputs and dates accompany them. Remaining gaps — units, edge-case output when nothing verifies — are minor for a read-only single-parameter tool.

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?

Only one parameter (ticker), already documented at 100% schema coverage including its pattern and an example. The description adds modest meaning by tying the ticker to SEC-filed financial data, but supplies no additional format, casing, or resolution behavior beyond what the schema states, so the baseline 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?

Specific verb ("Inspect") plus a precisely scoped resource: profitability and balance-sheet ratios, with the exact ratio families enumerated (gross/operating/net/cash-flow margins, liabilities/assets, LT debt/assets, cash/LT debt). The closing exclusion clause ("No stock price, valuation multiple, analyst estimate, score or buy verdict") cleanly separates it from valuation- or signal-oriented siblings such as get_stock_fundamentals or get_smart_money.

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?

Usage boundaries are conveyed through explicit negatives rather than a named alternative: an agent learns to avoid this tool when it wants price, valuation multiples, analyst estimates, or a score/verdict. That is strong when-not guidance, but there is no positive when-to-use framing or a named sibling to route to, keeping it short of a 5.

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