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

Goes well beyond the annotations (readOnly=false, destructive=false) by disclosing the internal mechanics (layers inlined, re-keyed to fresh ids, pinned to an immutable source version) and the crucial non-propagation guarantee: edits to inner layers affect only THIS video. That is exactly the kind of behavioral context annotations cannot express.

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-loads the core action in the first sentence and keeps each subsequent sentence purposeful (mechanism, params, local-edit semantics, identification cue). It is slightly dense at six sentences, but no sentence is redundant with the schema or annotations.

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 mutating tool with an output schema (return values needn't be explained), the description covers purpose, mechanics, parameter roles, side-effect scope, and a distinguishing identification cue via describe_video. Nothing an agent needs in order to invoke it 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 coverage is 100%, so the baseline is 3, but the description adds conceptual framing that the schema lacks: it explains the host-vs-source relationship (projectId = the project being mutated, source_morpha_id = the project being embedded) and that version is an optional label. This clarifies how the parameters relate rather than merely restating them.

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?

Names a specific verb+resource (embed another project as a version-pinned band) and immediately describes the resulting artifact (inlined layers, collapsible group, re-keyed ids). It also explicitly distinguishes the produced band from a plain group ('describe_video marks an embedded band with morpha:true'), so an agent can tell it apart from group_layers.

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?

Gives clear operational context: which id to pass (source_morpha_id), the optional version label, and the re-pin path via the editor Inspector. However, it does not name or exclude the potentially confusable siblings (add_embed_origin, set_embed_origins), leaving the agent to infer when embed vs. embed-origin is appropriate.

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