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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so safety is covered. The description adds useful behavioral context that the response is a complete reference document (potentially large), helping the agent anticipate output size, though it doesn't state format or size explicitly.

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 sentences, front-loaded with the action and return content, then the invocation condition. Nothing is repeated or wasted.

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 help tool with no output schema, the description tells the agent what the returned document covers, which is the key decision input. Minor gap: it doesn't note the output format or approximate size, which matters for a "full" reference document.

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 takes zero parameters, so there is nothing for the description to disambiguate; this meets the baseline for a no-param tool. The schema coverage is 100% and the empty schema matches the description's implied no-argument invocation.

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?

States a specific verb and resource ("Return the full Muninn help document") and enumerates what it contains: what Muninn is, usage, and the full tool and skill reference. This clearly separates it from functional siblings like muninn_onboard or muninn_skill_registry.

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?

Gives an explicit trigger: "Call this whenever the user asks for help or how to use their memory." That is a clear when-to-use rule, though it does not contrast against adjacent discovery tools such as muninn_onboard or muninn_session_boot.

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