Activate license

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

With no annotations provided, the description carries the full behavioral burden. It discloses that verification happens offline against a built-in public key, that the key is persisted to the config file, and that invalid keys are refused and left unsaved. This is substantial transparency for an activation tool, though it could mention overwriting an existing key or the exact return behavior.

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 description is two sentences with no filler. The first sentence front-loads the main action, source, verification method, and persistence. The second sentence efficiently covers error handling and points to the related read-back tool. Every clause adds value.

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 a single-parameter tool with no output schema and no annotations, the description covers activation behavior, verification mechanism, persistence, error outcomes, and how to read the result later. The only minor gap is an explicit statement of what the function returns upon success or failure, but the phrase 'refused, unsaved' implies a feedback mechanism. Overall, it is sufficiently complete for an agent to call it correctly.

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 schema already documents the 'key' parameter at 100% coverage, so the baseline is 3. The description adds meaningful semantics by giving the concrete key format ('MCPL1.xxx.yyy'), confirming the key comes from the checkout page, and explaining that malformed or expired keys will be rejected. This goes beyond the schema's one-line 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 action ('Activate a Pro key'), the exact key format ('MCPL1.xxx.yyy'), the source ('from checkout'), and the core mechanism ('verified offline against a built-in public key'). It also differentiates itself from the sibling license_status by noting that license_status reads the activation back, so there is no ambiguity about which tool does what.

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?

The description gives clear context: use this when you have a Pro key from checkout that needs to be activated. It also points to license_status as the read-back tool, which implies when to use a related sibling. It does not explicitly spell out 'do not use for checking status' or list other alternatives, but the context is strong enough to avoid misuse.

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