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

Beyond the annotations, it discloses that activation returns 202, that checking happens in the background with a six-hour refresh and shared caches, what the page slot and PageSpeed quotas cover, the 30/15/7-day expiry alert cadence, and that entitlement is re-verified before collection and delivery. It also explicitly bounds behavior ("never makes a new purchase", "No takeover test is made"), which is exactly the kind of context annotations cannot convey.

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 action and prerequisite are front-loaded, but the text runs to roughly eleven clauses and repeats the no-purchase point three ways ("never makes a new purchase", "No separate charge", buy the pass at POST /api/plans/:id). The closing sentence about rechecking account, organization and paid right is ambiguously phrased and reads like an internal instruction rather than tool behavior.

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 an open-world, non-idempotent mutation with no output schema, the definition covers prerequisites, error codes, async semantics, coverage scope and alert cadence well. The main gap is what happens to existing watches, alerts and history when enabled is set to false.

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 100%, so both id and enabled are already documented, and the description adds only that the boolean is an explicit requested state (start vs stop) and that the id must be an owned page. That is a small clarification over the schema rather than new semantic detail, so the baseline 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?

"Start or stop dependency checks for an owned page" gives a specific verb (start/stop) and resource (dependency checks) plus scope (owned page), which lets an agent separate it from a one-shot audit tool. It does not explicitly name a sibling such as audit_dependencies, so differentiation is inferable rather than stated.

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 states a hard prerequisite (an existing paid watch pass), the exact failure mode when the prerequisite is missing (409 dependency_watch_plan_required), and the remedy path (buy the pass at POST /api/plans/:id). It does not explicitly say when to prefer this over a one-time dependency audit, so guidance is strong but not complete.

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