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

Annotations declare readOnlyHint=false and destructiveHint=false, and the description's 'active l'accès premium' is consistent with a state-changing but non-destructive write. It adds a genuinely useful behavioral detail: the code is passed through as-is with no normalization. It omits idempotency, error behavior for bad codes, and any rate or retry constraints.

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 tight sentences with zero waste; the action is front-loaded and the qualifier about code handling follows immediately. Nothing is repeated from the schema or annotations.

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?

An output schema exists, so return values need not be explained, and the annotations already carry the safety profile. The description covers what is done and how the input is treated, leaving only failure-mode behavior unspecified for a single-parameter mutation tool.

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 0% for the single parameter, so the description must compensate. It does add real meaning about where the code comes from (post-payment confirmation page) and that it is transmitted unmodified, but it gives no format, length, or validation details. Partial compensation for a low-coverage schema.

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: it activates premium access using an access code received after payment. It also clarifies the code's origin (confirmation page), which makes the purpose unambiguous. It does not distinguish itself from siblings, though the sibling list (scenario comparison, estimation, simulation) suggests they are unrelated operations.

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?

Usage is implied rather than stated: the agent learns the code is issued after payment and shown on the confirmation page, which is the precondition for calling this tool. There is no explicit when-to-use, when-not-to-use, or named alternative, and no guidance on what to do if the code is invalid or already redeemed.

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