add_property_keyframe

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

With no annotations, the description carries the full behavioral burden. It usefully discloses a side effect (enabling time-varying/keyframing on the property) and that readback is verified, which is meaningful beyond the schema. However, it omits idempotency, failure behavior, permission requirements, and what happens if keyframing was already enabled, leaving notable gaps for a mutation tool.

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?

A single front-loaded sentence that packs the enable step, the add step, and the verification step with no filler. It is slightly crammed into one compound sentence, but every clause earns its place.

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 14-parameter mutation tool with no output schema and no annotations, the description covers the core action and notes the readback verification. It still lacks guidance on which of the many identification params (clip_name vs clip_index vs clip_node_id; property_name vs property_index) to prefer and on prerequisites, so it is adequate but not complete.

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 the schema already documents all 14 parameters, including the value normalization behavior and time_reference enum. The description only restates time_seconds and value generically and adds no syntax or format detail beyond the schema, so baseline 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 states a specific verb+resource: enable keyframing on a clip property and add a keyframe at a time with a value. It clearly distinguishes itself from get_property_keyframes, update_property_keyframe, and remove_property_keyframe via the 'add' verb. It does not explicitly name siblings or contrast with set_supported_clip_property, so it stops short of 5.

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?

Usage is only implied: 'supported clip property' hints that the property must support keyframing, but it never tells the agent to consult list_supported_keyframe_properties first or to use get_property_keyframes to inspect existing keys before adding. No explicit when/when-not or alternative routing is provided, so it is minimum-viable at best.

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