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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered by structured data. The description adds value beyond that by disclosing what each entry contains — the source, its license, and its refresh cadence — which matters because there is no output schema to reveal return shape.

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 front-loaded sentence stating the resource first and the per-item fields second, with no filler. Every clause conveys information an agent would otherwise lack.

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 simple, argument-free listing tool with no output schema, the description supplies the essential return context (source identity, license, refresh). It stops short of noting ordering, pagination, or whether the source set is fixed, but nothing critical is missing for correct invocation.

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 there is nothing for the description to disambiguate and the baseline applies. The stated return fields are the useful semantic content here, not parameter explanations.

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 gives a specific verb ('List') and a clearly identified resource ('where the AI image tool data comes from'), and it names the fields returned per source. It is distinguishable from the sibling list_* tools by its provenance framing, though it never explicitly contrasts 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?

There is no explicit statement of when to call this versus list_categories, list_courses, or list_places, and no prerequisite or exclusion notes. For a zero-parameter enumeration tool the intended usage is implied and fairly unambiguous, which keeps this at a minimum-viable level rather than lower.

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