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

Annotations declare destructive/idempotent/non-read-only, and the description adds substantial context beyond them: exceeding cap blocks new session creation, no charges accrue beyond the cap, only values at or below the current cap are accepted, and the admin-console workaround for raising it. It also flags the required api_key, addressing auth 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?

Dense but well front-loaded: the core action and unit come first, followed by consequences and the raise/remove path. Every sentence carries information, though the api_key note at the end is somewhat tacked on.

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?

There is no output schema, and the description compensates by disclosing the returned settings_url and its purpose, plus the auth requirement and the cap's effect. An agent has everything needed to call the tool and instruct the user 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?

Schema coverage is 100% and the schema already documents both parameters, including the '<= current cap' constraint on minutes. The description restates those same semantics rather than adding format, unit, or boundary details beyond what the schema provides, so 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?

States a specific verb+resource: setting the monthly (or billing-period for paid plans) connection-time cap, expressed in minutes. No sibling tool touches spending caps, so an agent can identify this uniquely from the name and description alone.

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?

Explicitly defines when-to-use and when-not: it can only lower the current cap, and raising/removing the cap must instead be done by the user via the returned settings_url in the admin console. Also states the consequence of reaching the cap (no new sessions, no overage charges). Nothing is left to inference.

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