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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds valuable behavioral context about what is returned in each mode—categories with counts, or per-template ideas and preview_urls—and instructs the agent to show preview links and let the user choose. It does not mention rate limits or auth needs, but those are less critical for a read-only listing operation.

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?

The description is front-loaded with purpose and next action, then cleanly separates the two conditional modes. It is well-structured and mostly efficient, though the phrase 'a quick way to a good video' is slightly promotional and could be trimmed without losing meaning.

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 read-only listing tool with no output schema, the description covers the essential return shapes for both modes, the optional aspect_ratio filter, and the recommended next step. Annotations cover safety, and the parameter semantics are sufficiently clear from the schema and description combined.

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?

Schema coverage is 100%, so the schema already documents both parameters, setting a baseline of 3. The description adds meaning beyond the schema by giving concrete example video_type categories, stating that the category result is authoritative, and clarifying that aspect_ratio optionally filters templates to '9:16' or '16:9'. This extra semantic context justifies a 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 states a specific verb (browse/list) and resource (Fabeo's template videos), and explicitly distinguishes two modes: without video_type returns categories and counts, with video_type returns template ideas and preview_urls. It also names the sibling create_from_template as the follow-up action, making it easy to tell apart from other listing tools.

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?

It clearly explains when to use this tool: as a quick route to a good video by finding a template to copy via create_from_template. It also defines usage patterns for both parameter configurations. However, it does not explicitly state when not to use it or contrast it with other listing siblings like list_videos, leaving a minor gap.

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