list_categories

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

With no annotations, the description carries the behavioral burden and usefully discloses that the tool reads current configuration and does not read any emails. It does not mention permission requirements or behavior when configuration is empty, but for a zero-parameter read-only listing it provides solid transparency.

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 short sentences: the first front-loads what is returned, and the second adds the key non-behavior. There is no wasted language.

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 listing tool with no output schema, the description identifies the returned content and explicitly rules out email access. Minor details such as ordering or empty-configuration behavior are omitted but do not prevent correct invocation.

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 parameter semantics baseline is 4. The description correctly adds no parameter detail because there are none to explain.

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: return the names and descriptions of email categories allowed in the current configuration. It also explicitly says it does not read any emails, which sharply distinguishes it from the classify_jsonl and classify_imap siblings that operate on email content.

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 the tool is used to discover available categories, but it does not explicitly say when to call it instead of the classify_* siblings or whether it should precede classification. No exclusions, prerequisites, or alternative-selection guidance are provided.

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