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

Annotations already mark this as read-only and non-destructive, so the bar is lower. The description adds useful behavioral scope: it caps comparisons at four companies, restricts to one year, and enumerates the exact comparison dimensions, which tells the agent what kind of result content to expect.

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?

Two tightly packed sentences with no filler. The core capability is front-loaded, and the routing guidance to find_companies and sector_stats appears immediately after.

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 simple read-only tool with two well-documented parameters and no output schema, the description is complete: it states the input constraints, the data dimensions returned, and the related tools needed for correct invocation.

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 the schema fully documents both parameters. The description mostly restates the same limits (up to four codes, one year) without adding deeper meaning about parameter formatting or behavior beyond what the schema already provides.

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 a specific verb ('Compare') and resource ('companies') with concrete constraints: up to four companies, one year, and four data dimensions (accounts, tax debt, distress, revenue percentile). It also differentiates the tool from siblings by directing users to find_companies for code discovery and sector_stats for industry medians.

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 explicitly tells the agent to use find_companies first to discover registry codes and sector_stats when an industry median is needed instead of named-peer comparison. This gives clear when-to-use and alternative-tool guidance.

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