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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds useful behavior beyond those: results are limited to what the credential can read, the default organization is marked, and the returned slug is meant for downstream calls. This is meaningful context without contradicting the 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?

Two sentences with no filler. The purpose is front-loaded, and the usage instruction follows immediately. Every sentence earns its place.

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, the description is complete: it says what is returned, when to call it, and how to use the output. The lack of an output schema is mitigated because the description clearly conveys the key output concept (default-marked organizations with slugs).

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 tool has zero parameters, so the baseline is 4. The description adds no input-parameter meaning because there are none, but it usefully explains that the output's organization slug should be used as the `org` parameter in later calls, which helps the agent understand the data flow.

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 states a specific action and resource: 'Lists the organizations this credential can read, with the default one marked.' This clearly differentiates it from sibling tools like list_event_names and makes the tool's scope (credential-readable organizations) explicit.

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 explicit when-to-use guidance: 'Call it first when the user names an organization, or when another tool answers that no default is set.' It also tells the agent exactly how to use the result: pass the organization's slug as `org` on every later call.

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