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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds valuable context about the output content (specific metrics), a concrete example with numbers, and the data source (Stratalize tables), which goes beyond the annotations without contradicting them.

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 four sentences long, each serving a distinct purpose: usage context, output list, illustrative example, and source attribution. It is informative without being bloated, though the example could be considered slightly verbose.

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 lack of an output schema, the description compensates by listing the metrics returned and providing a concrete example. It explains the use case and source, making the tool's behavior predictable. It stops short of detailing return format or parameter interactions, but overall completeness is high.

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%, so parameters are already well-defined. The description adds the concept of 'ARR band' and an example, but does not elaborate on how optional parameters like burn_multiple or growth_rate_pct affect the results. This is adequate but not a major enhancement over 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 explicitly states the tool 'Returns Rule of 40, burn multiple, CAC payback, NRR, gross margin, and ARR growth targets by ARR band,' which is a specific verb+resource that clearly defines its function. It also distinguishes itself from sibling tools by focusing on SaaS financial metrics, not generic benchmarks.

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 explicit usage context: 'Use when assessing SaaS company financial health, preparing investor reporting, or benchmarking KPIs before a fundraise or board presentation.' It does not explicitly mention when not to use or name alternatives, but the 'Use when' phrasing gives clear situational guidance.

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