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

Annotations show this is a write operation (readOnlyHint=false), and the description confirms a mutation ('Place onto... timeline'). The description adds the prerequisite of a prior upload, which is useful, but it does not disclose other behavioral traits like validation of audio type, error cases, or reversibility. With minimal annotation detail, the description carries some burden but leaves gaps.

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 two sentences long, front-loaded with the core action and resource, and every word provides value. It does not waste space with redundant information.

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?

Given the tool's complexity (8 params, output schema exists), the description covers the primary use case, prerequisite, and audio-specific scope. It does not explain nuances like the required durationSeconds condition, but those are in the schema. It is adequately complete for an agent to decide when to use it.

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 description coverage is 100%, so all parameters are already documented. The description adds context that the asset must be an uploaded audio asset and that placement occurs at a timestamp, which reinforces but does not extend parameter meaning. Baseline of 3 is appropriate.

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 clearly states the action ('Place'), the resource ('uploaded audio asset'), and the destination ('actual BlitzReels project timeline at a timestamp'). It distinguishes this tool from siblings by specifically mentioning audio (voiceover, music), which separates it from timeline_media_add.

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 description explicitly says 'Use after media_upload_file' and specifies the user intent ('add voiceover, music, or audio to a video'). This gives clear context for when to use the tool, but it does not mention when not to use it or explicitly name alternatives.

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