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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile needs no restating. The one genuinely additive fact is the coverage constraint — only places that actually have AI video tools are returned — but the return shape, ordering and whether results are nested or flat are left unsaid.

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 with the scoping filter in the right place and no filler. Every word earns its place; there is nothing to trim.

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?

The tool is simple and the annotations are rich, so little is required, but there is no output schema and the description never sketches what comes back — a flat list of names, a country→region→city hierarchy, or identifiers usable in search_listings. That ambiguity is the main consumer-facing gap in an otherwise clean definition.

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 schema-coverage question is moot. Zero-parameter tools have no semantic gap to compensate for, which sets the baseline at 4.

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) plus a specific resource set (countries, regions and cities), scoped by the filter 'that have AI video tools'. That scope clause cleanly separates it from siblings such as list_categories, list_sources and list_courses, which enumerate other resource types.

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?

Use is only implied: an agent can infer this is the facet-enumeration tool for geography, but the description names no alternative and gives no when/when-not condition. For a zero-parameter lookup tool the inference is easy, which keeps this above a 2, but nothing is stated explicitly.

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