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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds real value by disclosing that the document is 'cached' (potential staleness) and that source ids must be discovered first, but it says nothing about failure behavior for invalid ids or whether the cache is ever refreshed.

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 short sentences with no filler, and the core action plus required inputs are front-loaded before the discovery hint. Every clause carries information.

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?

An output schema exists, so return values need no explanation, and the annotations cover the safety profile. However, with zero schema descriptions across both parameters, the definition should say more about article_id and about what happens when a cached document is missing.

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 0% for two required parameters, so the description carries the burden. It restates that both are required and explains where 'source' values come from, but gives no guidance on the expected format of 'article_id' or whether it is a numeric id, slug, or opaque key.

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 ('Read a cached Learnosity document') and names the two required inputs, so an agent can tell it apart from list/search siblings. It does not clarify the boundary with search_docs_sources, but the read-one-document framing is clear.

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?

Provides a useful prerequisite ('Use list_docs_sources or learnosity://sources/index to discover valid source ids') rather than a when-to-use rule. It never states when to choose this over search_docs_sources or what to do when an id is unknown or stale, leaving usage largely implied.

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