activate_base_plan

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

With no annotations, the description carries the full burden; it does disclose two useful traits the schema cannot: the tool is a state-changing operation and it is gated by an environment flag. It does not say whether activation is reversible, whether an edit session plus commit_edit is required, what errors occur if the flag is off, or whether the mutation propagates according to latencyTolerance.

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 with the effect front-loaded and the gating condition second; nothing is wasted and nothing is 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?

For a four-parameter mutation tool with no annotations and no output schema, the definition covers the outcome and one operational precondition but omits the edit/commit lifecycle, permission expectations, and the fact that latencyTolerance affects propagation timing. Adequate to select the tool, thin for calling it confidently.

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 coverage is 75%, so the baseline applies — packageName, productId, and latencyTolerance already carry inline descriptions with a documented default. The description adds no extra meaning for any parameter, leaving basePlanId (the only undocumented one) to be inferred from its name alone.

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 names a specific verb (activate) and resource (base plan) and states the observable effect — the plan becomes purchasable by users — which cleanly separates it from siblings like deactivate_base_plan and delete_base_plan. It stops short of explicitly naming those alternatives, so it is clear but not fully differentiated in-text.

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 context is implied rather than stated: an agent infers 'call this when a plan should be buyable again,' and the description adds a concrete precondition (the PLAY_MCP_ALLOW_SUBSCRIPTION_ACTIVATION gate). It gives no guidance on when to prefer deactivate_base_plan versus delete_base_plan, nor on the edit/commit workflow that other sibling tools imply.

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