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

The annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds useful behavioral nuance beyond that: it returns the full entry when no locale is given, and a single-locale body when locale is specified. This clarifies the tool's conditional output without contradicting annotations.

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?

Three short sentences with no filler, and the most important action and resource are front-loaded. Every sentence adds distinct value: what it does, the locale conditional, and the prerequisite workflow.

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?

The output schema is present, the parameter schema documents both fields thoroughly, and the description covers the critical usage dependency on search/list_knowledge. Nothing necessary for correct invocation is missing for a simple read-only retrieve-by-slug tool.

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%, so the baseline is 3; the description earns a 4 by explaining the semantic effect of the optional locale parameter ('single-locale body') rather than just naming it. It also reinforces that slug identifies which knowledge unit to fetch.

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 verb and resource ('Get one knowledge unit by slug') and explains the conditional return behavior, clearly distinguishing it from list_knowledge and search. The title reinforces the resource type, so an agent can tell this from sibling get_* tools without opening the schema.

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 explicitly states when to use the tool: 'Use this once search or list_knowledge has given you a slug.' This gives clear retrieval workflow context and implies it is for fetching an individual known item rather than searching or listing.

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