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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description doesn't need to restate safety. It adds useful operational context beyond annotations: flat 148-credit cost, the specific POST endpoint and documentation file, and Starter/Pro plan gates. It doesn't describe output shape, but that gap is not a contradiction.

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 front-loads the key fact ('Growth rates (15 metrics)') and packs scope, cost, endpoint, documentation, and plan requirements into a compact block. The long metric enumeration is justified because it defines exactly what this tool covers, though the trailing semicolon-separated operational details feel slightly cramped.

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 100% schema coverage and read-only annotations, the essential parameter semantics are fully supplied elsewhere. The description doesn't explain response format or interactions between the seven parameters, and since there is no output schema, some of that burden falls on the description. The 15-metric list implies what the output contains, so the gap is noticeable but not severe.

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%, with detailed parameter descriptions for as_of_date, current_price, current_fx_rate, metric_group_id, formula_override, light_weight_mode, and accept_suggested_formula. The tool description adds only a plan-level note about formula_override, which is already reflected in the schema. Baseline 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 names the resource ('Growth rates') and enumerates 15 specific metrics, leaving little doubt this is the growth-metrics retrieval tool among the many get_* siblings. It relies on the title for the verb but the metric list and endpoint make the purpose 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 explicit metric list lets an agent infer this tool is for growth rates and rule out profitability, valuation, or cash-flow metrics. However, it never states when to choose this over alternatives like get_metrics_bundle or get_profitability_metrics, and it provides no exclusion guidance. The cost and plan notes are prerequisites, not usage direction.

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