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

Annotations declare non-read-only, non-destructive, open-world. The description goes beyond them with real behavioral context: it enforces the same access rules as a direct check-in, override bypasses those rules and does not charge the member, and the action is reversible via remove_reservation. It does not detail rate limits or the response shape, but the safety/reversibility profile is well disclosed.

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 purpose is front-loaded in the first sentence, and each following sentence adds distinct value (reservation modes, access rules, override, reversibility, auth). It is slightly dense, with the trailing API-key note feeling tacked on, but nothing is redundant.

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 3-parameter mutation tool with no output schema, the description covers purpose, access-rule behavior, override semantics, reversibility, and auth requirements. Return values are not described, but with no output schema that gap is minor.

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 baseline is 3, but the description adds meaning beyond the schema for override ('checks the member in anyway, as staff can in the Control Panel; an override does not charge the member'), clarifying an important billing side effect not present in the field description.

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 a specific verb and resource ('Check a member into a class') and immediately distinguishes two modes: reserved check-in vs. a walk-in without a reservation. It also names remove_reservation as the undo counterpart, so the agent can tell it apart from sibling tools 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 gives clear when-to-use context (reserved member or walk-in) and points to remove_reservation for reversal, plus an autonomy note ('runs without asking'). It stops short of explicitly stating when NOT to use it versus alternates like pushpress_book_class_reservation, so it is strong but not fully exhaustive.

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