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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and a closed-world scope, so the safety profile is covered. The description adds value beyond that by disclosing what each entry contains (license and refresh per source), which is the main behavioral detail an agent needs. It stops short of describing ordering, count, or whether the 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 that front-loads the action and resource and appends only the return-content detail. There is no filler, hedging, or repetition.

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-argument read-only list tool with rich annotations, the description covers purpose and the shape of each returned item. With no output schema present, one could ask for slightly more on the return structure (e.g., that each source is one entry), but nothing critical for correct invocation 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 zero parameters and the schema is empty with full coverage, so there is nothing for the description to disambiguate; baseline 4 applies. No parameter claims are made or 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 uses a specific verb ('List') with a clearly scoped resource (the data sources behind the HVAC contractor data) and even names the per-source attributes returned (license and refresh). It is distinguishable from siblings like list_categories, list_places, and get_stats, though it does not explicitly contrast itself with 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 provenance/attribution lookup, but there is no explicit when-to-use guidance, no statement of when another tool is preferred, and no prerequisites mentioned. Adequate for a trivial zero-argument list tool, but nothing is spelled out.

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