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

No annotations are provided, so the description bears the full burden of disclosure. It states that the tool 'provides key performance metrics over the past year,' but offers no detail on output structure, data availability, or potential limitations. The description adds little beyond what the name and schema already imply.

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 concise, consisting of two sentences that front-load the tool's purpose and key metric categories. It contains minimal fluff, though the phrase 'TTM Ratios API' is slightly redundant with the tool name.

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 tool is simple (one parameter, no output schema), and the description conveys the core purpose and metric types. However, without an output schema, it could more fully describe what the response contains (e.g., a list of ratio objects, units, or time periods), and it omits any mention of single-symbol scope.

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% for the single parameter (symbol: 'Stock symbol'). The description adds no additional meaning to the parameter, so the baseline score of 3 is appropriate.

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 ('gain access to') and resource ('trailing twelve-month financial ratios'), and lists included categories (profitability, liquidity, efficiency). It is clear what the tool does, but it does not explicitly differentiate from sibling tools like getRatios or getRatiosTTMBulk.

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 context about the purpose (TTM ratios) but gives no explicit guidance on when to use this tool versus alternatives. It does not mention that a single symbol is required or that bulk versions exist for multiple symbols, so usage guidance is largely implied.

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