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

With no annotations, the description carries the full burden. It adds one useful behavioral detail — the limit is a composite of base allowance plus purchased slots — which clarifies the returned value's semantics. But it does not disclose the return shape, whether the value is total capacity or remaining availability, or any other behavior. Adequate but not rich.

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 compact sentences, zero filler, with the core semantic (base + purchased slots) front-loaded and the use case right after. Every word earns its place.

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 simple 0-parameter getter, the description covers what the tool returns and when to call it. Minor gaps remain: no output schema exists, so the return format is only hinted at, and the boundary with the similarly named get_agent_plan_limits is unaddressed. Still, an agent has enough to invoke 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 tool has zero parameters, so the schema needs no documentation and the description rightly spends no space on params. Per the baseline for 0-param tools, this is a 4; there is nothing missing.

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 clear verb+resource: getting plan limits composed of 'Base + purchased extra agent slots.' The title reinforces the resource ('max agents, extra slots'). However, it fails to differentiate from the near-namesake sibling get_agent_plan_limits, so it scores below a 5.

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?

Provides concrete when-to-use context: check 'can I create another agent?' before calling create_agent. This is clear and actionable, but it gives no when-not-to-use guidance or explicit alternatives, such as why this over get_agent_plan_limits or get_subscription.

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