Certified Financial Arithmetic

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

The description adds 'Deterministic zero-error' behavioral context, which implies guarantees about output reliability not present in the readOnlyHint annotation. It also clarifies the data source 'verified SEC EDGAR financial metrics', giving insight into the tool's data provenance. This goes beyond the annotation while remaining consistent with read-only semantics.

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 sentence that efficiently conveys the tool's purpose, key operations, and data domain. Every word serves a purpose, and the parenthetical list of operations is a compact way to communicate scope. It front-loads the key aspects without superfluous details, embodying excellent conciseness.

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 moderate complexity (8 parameters, multiple operations) and the presence of an output schema, the description covers the essential context: what the tool does, its deterministic nature, and the data source. It omits usage scenarios or operation-specific details, but the schema handles parameter specifics. For a tool of this scope, the description is sufficiently complete, though it could theoretically mention whether operations are composable.

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 description does not elaborate on individual parameters, but the input schema provides descriptions for all 8 parameters (100% coverage). The description's mention of operation types indirectly relates to the 'op' parameter, adding marginal context. Since the schema fully documents parameters, a baseline of 3 is appropriate; no extra semantic value is added by the description.

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 states the tool is a 'Deterministic zero-error algebraic solver' and lists specific operations (cagr, ratio, multiply, divide, yoy_series, product_chain) over SEC EDGAR metrics, which clearly conveys its purpose. However, it does not explicitly differentiate itself from sibling tools like compute_sec_cagr, despite the overlap in CAGR functionality. The verb+resource structure is specific enough to understand the core function.

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?

No usage guidance is provided about when to choose this tool over the sibling tools (e.g., compute_sec_cagr). The description lists available operations but does not indicate scenarios where this tool is preferred or provide exclusions. There is no mention of alternatives or when not to use it, leaving the agent without explicit decision support.

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