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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so safety and idempotency are covered. The description adds useful return-content context by stating that each source includes license and refresh information. It does not describe pagination, ordering, or failure behavior, but for a no-param read-only list tool that is a minor gap.

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?

A single compact sentence that front-loads the verb and resource, then adds the key returned fields. Every phrase earns its place and there is no filler.

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?

With no parameters, no nested objects, and no output schema, the description carries a reasonable amount of context: it states what the tool lists and what each result contains. An agent has enough to call it correctly, though it could be slightly more complete by mentioning ordering or scope limits.

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 there are no parameter semantics to explain; baseline for 0 params is 4. The description correctly focuses on output content instead of inventing parameter guidance.

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 uses a specific verb and resource: 'List where the sleep clinic data comes from.' It also names the fields each item includes (license and refresh), making the purpose clear. It does not explicitly distinguish itself from siblings like list_categories or list_places, though 'sources' is reasonably distinguishable.

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?

Usage is implied by the description: an agent would call this when it needs provenance, licensing, or refresh information about the data. However, there is no explicit when-to-use guidance, no exclusion criteria, and no mention of alternatives among sibling tools.

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