list_categories

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

With no annotations provided, the description carries the full burden. It discloses the return structure ('each with its record count') and the case-insensitive substring filtering behavior, which gives a clear sense of what the tool does without side effects. However, it does not explicitly state that the operation is read-only or describe potential edge cases (e.g., invalid inputs, empty results), so it is not fully transparent but still strong.

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 well-structured with clear sections: main purpose, return value, args, and returns. Each sentence earns its place, with no redundant fluff. It is front-loaded with the most important information and uses a clean format for parameter details.

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 has one optional parameter, a clear output schema, and a well-defined use case, the description is complete. It explains what the tool returns, how to filter, and how it relates to sibling tools. The presence of an output schema means return format details are covered elsewhere, so the description does not need to over-explain.

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?

Even though the schema only lists 'contains' as a nullable string, the description enriches it substantially: 'Case-insensitive substring filter on the category slug; omit to list every category.' This explains the exact semantics, case-sensitivity, and the effect of omission, providing high value beyond the schema.

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 opens with a specific verb+resource: 'List the articulated-furniture categories in the articraft catalog.' It clearly states the tool's scope and function, and distinguishes it from sibling tools by naming the related tool 'retrieve_articraft' and positioning this as the prerequisite discover step.

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?

Provides explicit guidance: 'Call this before retrieve_articraft to discover valid category names.' It also tells the user how to use the 'contains' parameter ('omit to list every category'), covering both the recommended use and the alternative behavior, which effectively communicates when to use this tool versus others.

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