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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is a non-idempotent, non-destructive write. The description adds that it acts only on the explicit project_id and returns project identity, but does not say what state is changed or created, which matters for a non-idempotent mutation.

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?

Three dense sentences with the scoping caveat front-loaded and no filler. The mixed use of English and pseudo-syntax (to='track:<id>') is slightly compressed but each sentence carries information, so little is wasted.

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 9-parameter, non-idempotent mutation with no output schema and 11% schema coverage, the description leaves key parameters (start, end, radius, label) and the nature of the mutation unexplained. It covers the project scoping and one downstream usage but is not complete enough to call confidently.

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 only 11%, so the description carries most of the burden, yet it only explains t, x, y and the track id convention while leaving id, start, end, radius, and label undocumented. The coordinates note is genuinely helpful, but five of nine params remain opaque in both description and schema.

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 action (follow a point through its shot / fx track) and clarifies the coordinate system (t and x,y in program fractions from look_at), which is enough to distinguish it from sibling add_* graphics tools. It falls short of 5 because the core resource being produced (a tracking marker/attachment) is implied rather than named outright.

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 gives useful context that the call is project-scoped and that the result feeds to='track:<id>' for attaching graphics, which implies a usage workflow. However, it never states when to choose this over siblings like look_at, select_object, or set_text_motion, nor any exclusions.

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