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

Annotations already declare readOnlyHint and destructiveHint. The description adds valuable behavioral context: the list is capped, sorted by revenue descending, does not include personal emails or phone numbers, and accepts county aliases. These are meaningful details beyond the structured annotations.

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 sentences pack a remarkable amount of information: cap, sort order, filter types, exclusions, alias acceptance, and usage guidance. Every word earns its place, and the core function is front-loaded.

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 tool with 9 optional parameters and no output schema, the description covers the essential behavioral aspects: cap and sort, exclusions, alias handling, and routing to sibling tools. It even implies the return contains company codes ('get_company on a code from this list'), which is a helpful hint. No critical information is missing 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 each parameter already has a clear description. The tool description mentions the filter categories (county, EMTAK, revenue, employees, no tax debt) but does not add new meaning beyond what the schema provides. Baseline 3 is appropriate when the schema carries the parameter documentation.

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 returns a capped list of companies sorted by revenue descending, with multiple filter options. It distinguishes itself from search_companies by explicitly noting it is not for name lookup, making 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 description explicitly directs users to 'Use search_companies for a name lookup, and get_company on a code from this list.' This tells the agent exactly when to use alternatives, eliminating ambiguity about tool selection.

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