list_categories

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

Annotations already declare readOnlyHint, openWorldHint=false, and idempotentHint, so the safety profile is clear. The description adds behavioral context about what data is returned (category descriptions, page counts, page slugs/titles) and distinguishes the dimension from components. It does not explicitly state that it takes no parameters or that results are static, but the schema covers the parameter side.

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 compact and front-loaded: it states the return shape first, then enumerates categories, then gives cross-tool guidance. The category enumeration is slightly dense but informative; every sentence contributes to selection or invocation.

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-param, read-only listing tool with no output schema, the description is complete enough to call correctly: it says what is returned, when to use siblings, and how categories are structured. The lack of an explicit statement that no parameters are accepted is a minor gap covered by the schema.

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?

With zero parameters and 100% schema coverage, the baseline is 4. The description correctly implies no inputs are needed and spends its words on output content instead.

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 verb (List) and resource (rule categories in the Email Playbook) and explains exactly what each entry contains (one-line description, page count, slug/title). It also enumerates the four categories, making the tool's scope unambiguous.

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 explicitly routes the agent: 'Pass a page slug to get_rule to fetch just that page' and 'For reusable components, use list_components instead — they live in a separate dimension and are not returned by get_playbook_rules.' This names alternatives and their conditions.

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