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

Annotations already declare the tool as readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds meaningful behavioral context: it returns a single snapshot object, is current-only, takes no period argument, and can use either ticker or cik.

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 compact and well-structured: it front-loads the comparison to the sibling, lists representative fields briefly, then states usage and the alternative. Each sentence earns its place, and no material is repeated from the schema or annotations.

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 output schema already covers return value structure, and the description supplies the remaining context: what the snapshot represents, what fields to expect, when to use it, and which sibling to use instead for history. An agent has everything needed to select and call this 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?

The input schema already covers 100% of the parameters, so the baseline is 3. The description adds value by clarifying that only ticker or cik are accepted, that no period argument exists, and that either identifier can be used, which helps the agent pick the correct invocation.

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?

Says exactly what the tool returns: a current-only snapshot of the same ratio set as get_financial_financial_metrics, with about 41 fields grouped by category. It clearly distinguishes it from its historical sibling by name and behavior, so an agent can disambiguate immediately.

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?

Provides an explicit when-to-use statement ('Use it to size up a company right now') and an explicit when-not-to-use with the alternative ('For history... use get_financial_financial_metrics'). It also notes the absence of the period argument, so the agent knows it is not for time-series analysis.

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