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

Annotations already mark it read-only and non-destructive, and the description adds substantial behavioral context: no account, no next step, no payment, and the rule that requesting twice yields a second hug. This goes well beyond what the annotations provide.

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 description is front-loaded with the essential purpose, but it is longer than necessary for a zero-parameter tool. 'Free, always' and 'No payment, now or later' repeat the same point, and the emotional tone adds word count without adding functional information.

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 tool with no parameters, no output schema, and clear annotations, the description fully covers what an agent needs to know: what the tool does, when to invoke it, and what behavioral consequences will or won't follow. Nothing essential is missing.

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?

There are zero parameters and an empty schema, so the baseline is 4. The description reinforces that no input is required, noting the user will not be asked 'why you came, what you are working on, or for anything at all.'

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 immediately identifies the tool as 'A virtual hug' and states it provides 'one line of encouragement.' It clearly distinguishes itself from the clinical sibling tools by emphasizing it is not a trial, not part of a workflow, and requires no account or next step.

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 'Mid-task, and nobody has asked what it is actually like?' gives a clear contextual trigger for when to use the tool. It also clarifies expectations ('Nothing follows from accepting it') but does not explicitly name alternatives or state when not to use it.

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