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

Annotations already declare readOnlyHint=true, so no contradiction. The description adds useful behavioral context by clarifying it is not a content search and listing the exact categories and subcategories, which helps the agent understand what the tool will actually return. For a simple read-only listing tool, this is sufficient.

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 concise and front-loaded with the main purpose in the first sentence. The subsequent sentences provide necessary usage guidance and category details without wasted words. Every sentence serves a clear purpose, and the list of categories is well-structured with parentheses for subcategories.

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 simple list tool with an output schema and read-only annotation, the description fully covers what the tool does, when to use it, and what the input means. The output schema handles return-value documentation, so no further description is needed here.

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 provides an enum for the optional category parameter, but the description adds meaning by explaining the categories and giving examples of subcategories (e.g., discoveries includes AI, weapons, peds). This goes beyond the raw schema and helps the agent choose an appropriate category value.

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 it lists doc categories and their namespaces, using the specific verb 'list' with a defined resource. It also distinguishes itself from sibling tools by explicitly saying 'NOT a content search' and positioning itself as an orientation tool before browse/semantic_search.

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 usage context: 'Use once at session start (or when unsure) before applying a category= / namespace= filter to browse / semantic_search.' This tells the agent when to use it and implies when not to use it (not as a content search). It also provides the category list for reference.

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