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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new behavioral information: the tool's output depends on whether a guide is supplied, returning a list of guides or the guide text. With no output schema, this dual-mode disclosure is the main thing an agent needs and it is present.

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 compact sentence covering both modes, front-loaded with the resource name. Nothing is redundant, though the opening noun fragment is slightly cryptic and could have been fused more clearly with the mode logic.

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 two-parameter read tool with annotations covering safety and a description covering return shape, this is close to complete. Minor gaps: what the listing actually looks like and whether the language parameter affects guide selection or only the answer framing.

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?

Schema coverage is 100% with both parameters enum-constrained and documented, so the baseline is 3. The description does add the important semantic that the guide parameter is optional and its absence triggers listing rather than an error, which the schema alone (no required array) does not make obvious.

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?

Uses a specific verb (read) and names the exact resource (Ricuicui user documentation), then splits the two operating modes: with vs. without a guide. Sibling tools (get_latest_version, my_account) are unrelated, so no differentiation is needed. The only blemish is the terse opening fragment, which reads like a label rather than a purpose statement.

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 description implicitly tells the agent how to invoke each mode (omit the guide to list, supply one to read), which is useful usage context. However, it never states when this tool is appropriate versus other tools, nor any prerequisite such as needing to list guides before reading one. Guidance is implied, not explicit.

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