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

With no annotations provided, the description carries the full behavioral burden, and it does so thoroughly. It discloses that the source layers are inlined as a collapsible group, re-keyed to fresh ids, pinned to an immutable version, and that edits are local and never propagate back to the source. It also explains how embedded bands appear in describe_video output, giving the agent a complete picture of side effects.

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?

The description is front-loaded with the core action and immediately explains the important constraints. It is longer than one sentence, but every sentence earns its place by covering a distinct operational aspect: what the tool does, how layers are inlined, how pinning works, local-only editing, re-pinning, and detection. There is no filler or redundancy.

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 complex tool with no annotations and no output schema, the description is remarkably complete: it specifies inputs, the embedding semantics, the mutation behavior, and how to identify the result. The only notable gap is that it does not describe the return value or possible failure modes, such as what happens if the source project cannot be resolved, though the schema does cover the self-embedding constraint.

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 meaningful interaction semantics: source_morpha_id is explicitly named as the source project id, version is explained as an optional pin label, and the description clarifies that the server resolves and inlines the pinned version. It goes beyond repeating the schema by connecting each parameter to the embedding workflow.

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 names a specific resource ('another of the user's projects'), a precise action ('Embed'), and the resulting object ('version-pinned band'). It clearly differentiates this from siblings like add_embed_origin and create_project by explaining the cross-project embedding concept. An agent can tell exactly what this tool does without needing to inspect the schema.

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?

The description provides clear context for when to use the tool and how to handle the version-pinning workflow. It explicitly tells the agent that re-pinning to a different version should be done from the editor's Inspector, not this tool, and mentions describe_video for identifying embedded bands. It does not explicitly say 'use X instead of Y', but the operational context is strong enough for an agent to decide correctly.

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