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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered; the description goes further by spelling out exactly what each mode returns (folder paths with recursive document counts versus id/title/description plus immediate subfolders). That return-shape disclosure is especially valuable because no output schema exists, and it clarifies that ids are kollus:// resource URIs rather than opaque handles.

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?

Purpose and the no-path default come first, followed by the path-specific behavior, then the id/resource follow-up and the exclusion. Every clause earns its place, though the stacked parentheticals make individual sentences dense and slightly harder to scan than necessary.

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 single-optional-parameter read tool with no output schema, the description covers everything an agent needs: both return modes, the shape of returned fields, how to follow up on an id, and what content is out of scope. No annotation or schema gap is left unaddressed.

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 description coverage is 100% and the single path parameter is already documented in detail, including the "/" and "dev-guide/vod" examples and the optional kollus:// prefix. The description restates that meaning accurately but adds no syntax or edge-case detail beyond the schema, so the baseline of 3 applies.

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 names a specific action and resource: traversing the index of Kollus guides, error-code dictionary, supplementary guides, and anti-pattern docs as a folder tree. It also distinguishes the two operating modes (no path = full folder map; specific path = documents in that folder), so an agent can separate this browsing tool from search_docs or get_content_detail without opening schemas.

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 clear call patterns: omit path or pass "/" for the whole map, pass a folder path for a local listing, and read the returned id as an MCP resource when the body is needed. It also states an explicit scope exclusion (no OpenAPI specs or sample code), but never names a sibling tool such as search_docs as the alternative for keyword lookup, so routing guidance is implied rather than explicit.

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