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

Annotations already provide readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds behavioral context by positioning it as a session-initializer and noting that surfaces are product-bound (not category slugs), which prevents misuse. It doesn't contradict annotations, and the added context earns a high score, though it stops short of describing any edge cases like repeated calls.

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 lengthy but each sentence adds essential information: the entry-point role, the return taxonomy, the locked-vertical flag, capability kinds, surfaces, and a sample response shape. It is front-loaded with the 'call this first' directive. A minor reduction in verbosity would tighten it, but it remains efficient given the complexity.

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 parameterless tool with a rich output schema, the description covers all necessary context: what data is returned, how it relates to other tools, the distinction between surfaces and category slugs, and even an example response structure. Nothing an agent needs to invoke it correctly is missing.

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 tool has zero parameters, so per the rubric the baseline is 4. The description doesn't need to elaborate on parameter meaning, and it doesn't — it focuses on the output. This is entirely 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 explicitly names the resource ('Revuo directory') and the action ('briefs an agent'), and enumerates the full contents (taxonomy, categories, locked verticals, capability slugs, surfaces). It differentiates from siblings by declaring itself the 'Single call this first entry-point,' making its role unmistakable.

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?

Provides explicit when-to-use instructions: 'Use this once at the start of a session to ground every subsequent products.search / products.find_by_capability / tools.find_for_task call.' It also implies that subsequent tools are for follow-up queries, giving clear routing guidance.

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