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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false. The description is consistent with these, and it adds clarity by specifying the scope ('that the user is a member of') which is not explicit in annotations. It does not describe return format or pagination, but for a simple list operation with strong annotations, this is acceptable. No contradiction with annotations.

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 a single concise sentence that directly states the tool's purpose. Every word earns its place; there is no fluff, redundant phrasing, or extraneous details. It is appropriately front-loaded and efficient.

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?

Given the tool's low complexity (no parameters, simple read operation, no output schema), the description is nearly complete. The main omission is that it doesn't specify the output structure (e.g., array of organization objects) or mention that it returns only organizations where the user is a member, but that is already stated. The description suffices for an agent to invoke and understand the tool.

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?

The input schema has no parameters, and schema description coverage is 100% (vacuously). The description adds nothing beyond the schema, but the baseline for a zero-parameter tool is 4, as there are no parameters to document. The description unnecessarily restates the obvious, but it does not need to.

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 the tool lists all organizations the user belongs to ('Lists all organizations that the user is a member of.'). It explicitly scopes to the authenticated user's memberships, distinguishing it from sibling tools like supabase_get_organization (singular) and supabase_list_projects, though it does not explicitly contrast with them.

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 implies when to use the tool: when you need to enumerate organizations for the current user. However, it provides no explicit guidance on when not to use it or alternatives for broader organizational access or filtering. No exclusions or alternatives are mentioned.

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