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

Annotations already declare this is a non-read-only, non-destructive, closed-world mutation, so the safety profile is covered. The description adds the genuinely useful detail that 't' is clip-local rather than timeline-absolute, but it says nothing about what happens if no keyframe exists at t, whether the change is undoable, or what the call returns.

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 sentence with no filler, and the key qualifier ('clip-local time t') is placed where it is most needed. It is efficient but extremely sparse for a mutation tool.

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 small mutation tool with no output schema, the definition covers the core action and the meaning of 't', but given the low schema coverage and the missing edge-case behavior (no keyframe present, undo, error semantics), an agent still has to guess at failure modes.

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 only 25% (projectId alone), so the description must carry weight; it does clarify that 't' is clip-local time and that exactly one property keyframe is targeted. It leaves clipId and the prop enum entirely to the schema, which is acceptable since those are self-evident.

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 uses a specific verb and resource ('Remove the keyframe') and narrows scope to 'one property at clip-local time t', so it is clearly distinct from add_keyframe, set_keyframes, and clear_keyframes. It stops short of explicitly naming those siblings as alternatives.

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?

There is no when-to-use or when-not-to-use guidance. The agent must infer from the name alone whether to use this versus clear_keyframes (bulk removal) or set_keyframes (overwrite), and no prerequisites or preconditions are stated.

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