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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), so the bar is lower. The description still adds real behavioral context: values are computed only from matching verified SEC measurement periods, mismatched/unknown periods stay unknown, and each ratio retains source inputs and dates. That provenance and unknown-handling detail goes beyond what annotations provide.

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 purpose, then metric scope, then exclusions. The metric enumeration earns its length because it defines the tool's exact coverage, and there is no filler.

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?

With no output schema, the description usefully enumerates the returned ratios and their data provenance. It is nearly complete for a single-ticker read tool; the only gap is that it never explicitly positions itself against the fundamentals/earnings siblings that an agent might otherwise choose.

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) and schema description coverage is 0%; the schema carries a pattern constraint but no textual meaning, and the description never mentions the ticker argument. Ticker semantics are largely self-evident, so the schema's format pattern plus common sense keeps this at a baseline 3, but the description contributes nothing on parameters.

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 names a specific verb ('Inspect') and a precise resource ('profitability and balance-sheet ratios'), then enumerates the exact metrics (gross, operating, net, cash-flow margins, liabilities/assets, etc.). The closing negative scope ('No stock price, valuation multiple, analyst estimate, score or buy verdict') further sharpens the boundary against siblings like get_stock_fundamentals and get_company_earnings.

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 is implied rather than stated: the negative scope hints that valuation/estimates live elsewhere, but the description never explicitly says when to pick this tool over get_stock_fundamentals or get_company_earnings. There are no stated prerequisites or exclusions phrased as guidance.

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