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

Annotations already declare the tool as read-only and idempotent, so safety is covered. The description adds valuable context by disclosing the FolioFact Pro requirement and specifying the exact data returned (enterprise value, FCF/EV, OCF/EV yields), which goes beyond the annotations and helps the agent judge suitability.

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 a single, compact sentence that front-loads the core content (financial statements and valuation summary) and then notes the access requirement. Every phrase earns its place with no 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?

Given the tool's simplicity (one parameter), rich annotations (read-only, idempotent), presence of an output schema, and a description that lists both the data types and the Pro requirement, the description is fully sufficient for an agent to select and invoke the tool correctly. The output schema explains return values, so the description need not elaborate.

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 parameter descriptions (ticker with 'dots allowed'). The description adds no additional parameter information, but since schema coverage is high, the baseline of 3 applies. The description's mention of data scope (yearly/quarterly) provides some contextual link to what the ticker parameter retrieves, but no new semantic detail.

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 identifies the tool's function: providing financial statements (yearly and quarterly) and valuation summary metrics. This distinguishes it from sibling tools like stock_earnings (earnings data) and get_stock (basic stock info), making the purpose specific and unambiguous.

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 implies usage when one needs financial statements or valuation metrics, but it does not explicitly state when to use this tool over alternatives or provide exclusion criteria. The mention of 'Requires FolioFact Pro' is a prerequisite, not a usage guideline. No explicit alternatives are given.

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