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

Annotations already declare the mutation, idempotency, and non-destructive profile, so the description's job is to add behavior detail. It does so by explaining that an unassigned flow falls into the default solution when `solution` is omitted, and that the operation is additive rather than a move ('stays in the one it is in'), which is context the agent could not infer from hints alone. It still says nothing about permissions 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?

Three tight sentences, front-loaded with the purpose and followed by the two conditional cases. The repetition of 'and stays in the one it is in' is slightly wordy but earns its place by preventing an incorrect 'move' mental model.

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 four-parameter mutation tool with no output schema, the description covers purpose, input selection, and the nuanced assignment semantics adequately. It does not describe permissions requirements or failure modes, which would round out an otherwise complete definition.

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; the description exceeds it by clarifying the condition under which `solution` can be omitted (unassigned flow) versus when it is needed, and by stating the mutual exclusivity of `flowName` and `app` in behavioral terms rather than just field notes. The default-solution outcome is genuinely new information not in the 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 opening sentence names a specific verb and both supported resource types ('Add a flow or a canvas app to a solution'), which is precise enough that an agent can identify the operation without opening the schema. No sibling tool in the list performs solution assignment, so no explicit sibling contrast is needed.

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 the selection rule between the two mutually exclusive inputs ('Pass flowName or app') and describes the conditional behavior for flows not yet in a solution versus entities already assigned. What is missing is explicit guidance on when this tool should be chosen over an update-style sibling or what prerequisites the caller must satisfy.

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