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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds a genuine behavioral fact beyond them: the returned values are identifiers, not human-readable labels, which changes how the agent must use the result. It stops short of describing ordering or any edge cases, so not a 5.

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 short sentences, zero waste. The purpose is front-loaded and the actionable prerequisite follows immediately, with the reason appended rather than buried.

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?

A zero-parameter lookup tool with an output schema and full annotations needs only to say what it enumerates and how to consume the result — both are present. Nothing an agent needs in order to call 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 takes zero parameters, so there is nothing to disambiguate; baseline is 4. The description usefully redirects parameter semantics to the downstream tool by noting that `seminars_search`'s difficulty filter expects an identifier.

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?

States a specific verb ('Lists') and resource ('the difficulty levels a seminar can be filtered by'), and the enumeration framing distinguishes it from sibling lookups like seminar_topics and seminar_locations. An agent can immediately tell this is a lookup/enumeration tool, not a search tool.

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?

Explicitly prescribes the call sequence: 'Call this before passing `difficulty` to `seminars_search`', naming the exact sibling and the exact parameter it feeds. It also explains why the prerequisite exists (the filter takes an identifier, not a label), which is precisely the kind of routing information an agent needs.

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