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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and closed-world scope, so the safety profile is fully covered. The description adds the content scope of the listing, but says nothing about whether the list is static or dynamic, how large it is, or how the language parameter shapes the results — which matters because the schema says titles come back localized.

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?

One sentence, front-loaded with the verb and the payload, with zero filler. Slightly dense colon-list phrasing but no sentence is wasted.

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 parameterless read-only enumeration with full annotation coverage and a fully documented schema, the description names all three returned content types, which is the key thing an agent needs. Only the interaction between the language parameter and the returned labels is unaddressed.

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?

There is a single optional parameter (language) and schema description coverage is 100%, fully documenting codes, effects on titles/summaries/links and the 'en' default. The description adds nothing about it, which is acceptable at full coverage but is a missed opportunity to note that the listing itself is localized.

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?

States a specific verb ('Lists') and enumerates the exact resource contents: video models, categories, and camera/light/style techniques. It also ties itself to the sibling 'search' by framing the output as 'what search can filter on', which makes its role distinguishable without naming fetch. It stops just short of a 5 because it never distinguishes itself from 'fetch'.

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?

The phrase 'what search can filter on' implies the intended workflow (call this to discover valid filter values before searching), but that inference is left to the agent. There is no explicit 'use this when...' instruction and no statement of when not to call it or what to do instead.

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