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

Adds real context beyond the annotations: the idempotent behavior is grounded ('if the element is already in the project, returns the existing Asset ID'), the non-obvious branch semantics (write a version without switching the editor) are disclosed, and the return value is named. The 'returns existing Asset ID' phrasing partly restates idempotentHint=true, but the branch-write behavior is genuinely extra.

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?

Front-loaded with the core action and the search_elements dependency; each sentence carries routing or behavioral information. A few telegraphic fragments and the 'Bind analysis with transcript=, beats=, audio=, or track=' line are dense and slightly disconnected, keeping it below a 5.

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?

With no output schema, the description correctly names the return value (Asset ID), covers the idempotent-return case, the branch/version behavior, and the downstream placement step. Nothing an agent needs to invoke this 3-param mutation correctly is missing.

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 baseline is 3, but the description adds provenance and a guardrail ('Pass elementId from search_elements', 'Do not invent ids') that the schema does not state. branchId and projectId semantics largely echo the schema rather than extending it.

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?

States a specific verb+resource ('Import a published library element into the project as-is') and immediately disambiguates from siblings: elementId comes from search_elements, source/inputs are fixed by the library, and replace_component is named as the wrong tool for plain copying. An agent can distinguish this from add_from_library, scaffold_component, and read_element without opening schemas.

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?

Explicit routing: fetch elementId via search_elements, place the result with patch_film, and a clear when-not ('Do not use replace_component to copy the source unless you need to change it'). The branchId condition (null = current version; version id = write that version without switching the editor) is spelled out rather than left to inference.

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