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

Annotations fully cover the safety profile: readOnlyHint=true, destructiveHint=false, openWorldHint=false, and idempotentHint=true. The description adds useful context about the returned plan attributes (prices, limits, features), which matters since there is no output schema.

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?

It is a single, front-loaded sentence with no waste. The key action and returned content are conveyed immediately.

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 no-parameter, read-only listing tool with rich annotations and no output schema, the description is largely complete: it says what the returned plans include. Minor gaps such as ordering or pagination are not relevant without parameters.

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 takes zero parameters and the schema is empty. Per the rubric, zero parameters gives a baseline of 4, and no additional parameter semantics are needed.

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 (List) and resource (MisarDev's plans) and specifies the contents returned: prices, limits, and features. It does not explicitly name sibling tools such as get_subscription or upgrade, so differentiation is implied 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 phrase 'what each upgrade would unlock' hints this tool is used to inspect plan options before upgrading, but it does not explicitly say when to use it versus get_subscription, get_usage, or upgrade. Usage context is implied, not defined.

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