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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive). The description goes further by disclosing the data-merging behavior (real Supabase enrollments blended with the marketing curve via computeEffectiveSlots) and the guarantee that availability is never overstated — genuine behavioral context beyond structured fields.

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?

Three tight sentences, front-loaded with the purpose followed by the guarantee and the soldOut action. No filler, though the parenthetical function name is somewhat internal-facing.

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?

There is no output schema, so the description carries some return-value burden; it names soldOut explicitly and hints at the slot count, but doesn't enumerate the full response shape. For a single-parameter read tool it is nearly complete.

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 single slug parameter is already fully documented including an example. The description adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 (checa) and resource (vagas restantes na próxima turma de um curso), and scopes it to the upcoming class, distinguishing it from list_upcoming_classes. An agent knows exactly what it returns without opening the schema.

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 provides guidance for one outcome (if soldOut=true, direct the user to the WhatsApp waitlist), which is useful. However, it never explains when to pick this tool over siblings like get_course or list_upcoming_classes, so selection guidance is only partially implied.

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