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

No annotations are provided, so the description carries the burden. It indicates the operation returns a comparison (a read-like behavior) and specifies the input format (slug). However, it does not disclose any side effects, output structure, or data source details. Since this is a non-mutating retrieval tool, the minimal transparency is acceptable but not exceptional.

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 a single, concise sentence that front-loads the tool's purpose and includes an example. No unnecessary words or overlapping with schema details.

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?

This is a simple tool with one parameter and no output schema. The description adequately communicates the tool's core function and input format. It does not explain what the comparison includes, but for a straightforward retrieval of a comparison by slug, it is sufficiently complete for an AI agent to select and invoke the tool.

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?

The schema already documents the 'slug' parameter with a clear description and an example. The tool description also provides an example (droneshield-vs-dedrone), adding marginal value but not going beyond the schema's coverage. With 100% schema description coverage, a baseline of 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 states the tool performs a side-by-side company comparison, with the resource being companies and the mechanism being a slug. The title 'Get a company comparison' and the tool name 'compare_companies' reinforce the purpose. It clearly distinguishes from siblings like get_company_profile or get_briefing, which are not comparison-focused.

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 implies the tool is used when a side-by-side company comparison is needed, and the slug example shows how to specify the comparison pair. However, it does not explicitly state when to use this tool instead of alternatives, nor does it mention any exclusions or prerequisites.

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