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

Annotations already convey read-only, idempotent, and non-destructive behavior. The description adds a useful behavioral trait beyond annotations: it explicitly states that no character or credential is required, which is an important access requirement for an agent. The content description ('guides') is consistent with the read-only annotation.

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?

A single sentence is front-loaded with the crucial instruction ('Start here') and lists all content areas efficiently. Every phrase adds value, with no filler. It is an excellent example of concise, well-structured tool documentation.

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 orientation tool, the description adequately tells the agent what content will be available and that no credentials are needed. It does not detail the return format, but for this tool type the description provides enough context for an agent to decide when to call it and what to expect at a high level.

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 and 100% schema description coverage, so the schema already fully describes the parameters. Baseline 4 applies because with no parameters, the description does not need to compensate for anything, and it correctly provides context about tool behavior rather than parameters.

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 the tool is an orientation guide ('Start here') and lists the content areas it covers: purpose, privacy, identity, admission, actions, and world guides. It distinguishes itself as the introductory tool among siblings through the explicit 'Start here' signal, though it does not name a specific verb-resource pairing.

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 instruction 'Start here' provides explicit context for when to use this tool first, before other actions. It also adds a practical usage note: no character or credential is required, meaning the agent can safely invoke it without prerequisite setup. It does not, however, mention explicit exclusions or alternatives beyond the implied starting point.

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