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 the safety profile is fully covered. The description adds that each entry carries license and refresh metadata, which is useful context, but it says nothing about ordering, cardinality, or whether the source list is static.

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 sentence, front-loaded with the action and resource, and the useful return-field context (license, refresh) is packed in without waste.

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 trivial zero-parameter listing tool with no output schema, the description is nearly complete: it states what is listed and which fields accompany each entry. It could go slightly further by describing the shape of the response (e.g. a flat list of sources), but no essential information 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?

The tool takes no parameters, so the schema imposes nothing and the baseline is 4. The description correctly implies no inputs are needed to scope the result.

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 a specific resource (data sources for the heating contractor data), and clarifies that it is about provenance rather than listings. It is clearly distinct from siblings like list_categories, list_places, and search_listings, though it does not explicitly contrast itself with any of them.

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 only implied: an agent can infer this is the tool to call when it needs provenance/licensing information. There is no explicit when-to-use or when-not-to-use statement and no named alternative, but for a zero-parameter enumeration tool the intent is reasonably self-evident.

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