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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description adds valuable operational context beyond that: the fixed credit cost, the HTTP endpoint, the documentation reference, and plan-level authentication requirements. Mentioning that formula_override is Pro+ is especially useful before invocation.

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 two tightly packed sentences with no filler: it front-loads the returned metrics, then gives cost, endpoint, documentation, and plan restrictions. Every clause adds actionable information.

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?

For a read-only metrics tool, this is complete: it enumerates the exact output metrics, gives the endpoint, cost, documentation path, and plan requirements, while the input schema fully covers all 7 parameters. Even without an output schema, an agent has enough context to understand inputs and expected results, including the lighter payload option.

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%, and each parameter already has a detailed explanation, including defaults, constraints, and semantic behavior (e.g., as_of_date cutoff, current_price limitations). The description's plan-requirement note for formula_override largely restates what the schema already says, so it adds no meaningful parameter guidance beyond the schema.

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 states the exact resource—'Turnover ratios and working-capital days'—and enumerates all 10 returned metrics, making it immediately distinguishable from sibling metric tools like get_profitability_metrics or get_valuation_metrics. It also names the concrete endpoint, POST /api/v1/metric/efficiency, so the operation is 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 provides relevant usage constraints, including the flat 148-credit cost and the plan requirements ('Requires the Starter plan or higher; formula_override requires Pro+'). However, it does not explicitly explain when to choose this tool over alternatives such as get_metrics_bundle, get_metrics_subset, or other metric-specific tools; the usage context is implied by the metric names rather than stated.

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