tracks_set_keys

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

Beyond the destructiveHint=true annotation, the description discloses concrete consequence detail: delete removes existing nonzero keys including the final key while retaining frame 0, and insert only works on unlocked tracks. That is real value the annotations don't convey. It still omits whether insert overwrites existing keys, how locked tracks fail, and atomicity, so it is not fully transparent.

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 tight sentences with the destructive branch front-loaded and the extend_timeline caveat trailing—no filler. The phrase 'explicit unlocked tracks' is terse to the point of being slightly cryptic, keeping it just below top marks.

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 destructive mutation tool with four undocumented parameters and no output schema, the description covers the core behavior but leaves gaps an agent would want: track identifier format, failure behavior on locked or missing tracks, and whether insertion replaces existing keys. Adequate but incomplete given the tool's complexity.

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?

With 0% schema description coverage across 4 parameters, the description must carry the load; it does explain extend_timeline and the insert/delete semantics of mode, and 'retaining frame 0' hints at the frames parameter. But the tracks parameter (what identifier to pass) and the frames parameter's index semantics and bounds are left unexplained.

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 pair (insert/delete keys) applied to a named resource (tracks) and distinguishes the two modes ('Insert keys on explicit unlocked tracks, or delete existing nonzero keys...'). It is clear enough to tell what the tool does without opening the schema, though it never names or contrasts a sibling tool.

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 implies when each mode applies and gives an explicit prerequisite for extending animation ('Extending animation requires extend_timeline=true') plus a constraint that tracks must be unlocked. However, it offers no guidance on when to prefer this over related siblings such as tracks_retime, tracks_select_frames, or tracks_set_interpolation, leaving the agent to infer the boundary.

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