Tag a scene

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

Annotations only set destructiveHint=false; the description adds that an API key with the Editor role is required, clarifying this is a privileged write operation. It does not cover idempotency or duplicate handling, but the auth context is valuable beyond annotations.

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?

Two sentences, front-loaded with purpose and scope, then the auth prerequisite. No wasted words.

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 two-parameter tagging tool with full schema coverage and a destructiveHint annotation, the description covers purpose, scope, and auth. Return values aren't needed without an output schema, so it is complete enough.

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%, with both parameters documented. The description adds no syntax or format details beyond the schema's 'comma-separated keywords' and 'thumbnail's id', so baseline 3 applies.

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 'Add keywords' and resource 'single scene thumbnail', explicitly distinguishing from tagging the whole video. An agent can tell it apart from sibling tag_video without opening schemas.

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?

Provides clear context for use—tagging an individual scene thumbnail rather than the whole video—but does not name the alternative tool (tag_video) or state exclusions. The implied usage is clear, yet explicit routing is absent.

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