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

The annotations already provide read-only, idempotent, and non-destructive hints, so the description's own 'does not create a project' is largely redundant. However, it does add behavioral scope beyond annotations: the caller only sees projects they own or are invited to, and the output will expose ids, names, and suffixes. That extra context moves it slightly above the annotation baseline.

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 earns every word. The first sentence establishes the scope, the second routes to sibling tools, and the last confirms no side effects. It is tight, front-loaded, and there is no filler.

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 zero-parameter, read-only list tool, this is complete. It describes the input scope, the output fields, and the proper sibling tools for follow-up, while the annotations cover idempotency and safety. No output schema is required because the description already says what will be returned.

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?

There are zero parameters, so the description does not need to explain parameter semantics. It still orients the agent by describing what the output contains (ids and names), which is appropriate for a parameterless list tool.

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 clearly states a specific action ('List') and a specific resource ('hosting projects the caller owns or is invited to'), while also noting the returned fields (ids, names, suffixes). It distinguishes this from siblings by explicitly pointing to get_project and get_preview_url, so any agent can tell exactly what this tool does.

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?

This description gives explicit alternatives: use get_project for one project's settings and get_preview_url for the public URL. It also frames the intended case as listing all owned/invited projects, which is exactly the routing guidance an agent needs.

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