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

Annotations already fix the safety profile (readOnly=false, destructive=false, openWorld=false), so the bar is lower. The description adds real context the annotations don't: the created artifact is a persistent working copy with a known file layout, and the call returns a project_id. It stops short of noting idempotency, error behavior, or permission needs.

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?

One tight sentence with the scoping detail parenthesized, plus a short return-value clause. Front-loaded and free of filler, though the file-list parenthetical is the only mildly expendable element.

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 creation tool with 100% schema coverage and no output schema, the description covers what it makes and what it returns. Missing only peripheral information such as error conditions when a project already exists or required context/permissions.

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% with all three parameters fully documented (duration tolerance, resolution, aspect ratio default), so the schema carries the semantics. The description adds nothing about parameters, which is the expected baseline 3.

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 ('Creates an Ad Agent project') and elaborates on what that means concretely (assets/, gen/, index.html, stage.js). It also names the return value. It does not explicitly contrast itself with composer_project_get/list, but the create-vs-read distinction is self-evident.

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?

Usage is only implied: 'kept across conversations' hints that this is for work that must persist, but there is no explicit when-to-use, when-not-to-use, or mention of the sibling project tools. An agent can infer intent but is given no routing guidance.

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