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

With no annotations, the description carries the safety burden. It clearly warns that invalid auth leads to a payment_required envelope with next_actions, which is a behavioral trait. It also mentions the schema_version, implying structure stability. This goes beyond a simple 'returns data' statement, though it could disclose limitations like rate limits or whether results are sorted.

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 total, both information-dense. The first states the output and structure, the second the auth requirement and fallback behavior. No fluff; each clause earns its place.

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 rich output schema and clear parameter schema, the description covers auth, output format, and key variants. The tool is low-complexity (single required parameter), so nothing critical is missing. The description compensates for the lack of annotations.

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 baseline is 3. The description adds value by explaining the verbosity effect ('compact trims lesson bodies and drops narrative prose') and mentioning the envelope structure, which helps understand how max_results interacts. This is more than schema descriptions alone.

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 identifies a specific verb ('Returns') and the resource ('full Younanix Arete V7 lessons'), and adds a distinctive detail—the agent-native envelope with fields like root_cause and lesson_learned—that distinguishes it from sibling tools such as query_lessons. Purpose is 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?

It specifies the required authentication (x-agent-key header) and hints at the context (admin-issued key), which is valuable. However, it does not compare to siblings like query_lessons_premium or query_lessons, so when to use this tool over them is not stated. Still, the auth condition is a clear usage constraint.

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