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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), and the description adds real behavior beyond them: the copy lands in the same folder, it is not opened afterward, and the default name is "Copy". It stops short of saying what is carried over into the copy (versions, media, takes, brand), which matters for a duplication tool.

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 short sentences, front-loaded with the action and scope, then the alternative, then the post-condition. No filler and no repetition of the title.

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 two-parameter tool with annotations and no output schema, the description covers target selection, destination folder, and the side effect of not switching projects. The notable omission is whether it returns the new project's identifier, which the agent would need in order to chain into open_project.

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?

With only 50% schema coverage, the undocumented projectId is the weak point, and the description compensates by stating the default target ("the open one"). The name parameter's default is already in the schema, so the description adds no more there, but the projectId clarification is genuine value beyond 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?

States a specific verb and resource ("Copy a project ... into a separate new project") plus scope constraints (same folder, default is the open project). It explicitly distinguishes itself from two nearby siblings, create_variants and open_project, so an agent can pick it without opening a 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?

Names the alternative for a related-but-different need ("Use create_variants for versions of an ad") and clarifies the post-condition that selects open_project ("The copy is not opened: open_project moves to it"). Both a when-to-use and a when-to-use-something-else are present.

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