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

Annotations already declare readOnly, idempotent, non-destructive, non-openWorld behavior, so safety needs no restating. The description adds genuinely new context: "The full text is on christianpure.com", warning the agent that returned content is partial and a follow-up may be needed. It does not cover behavior for a missing/invalid article, which is the remaining gap.

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: what it returns, when to use it, how to call it, plus one constraint. It is front-loaded with the purpose and identifiers, and no sentence is filler.

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 read tool with no output schema, the description usefully enumerates the response fields, and the annotations carry the safety profile, so an agent has what it needs to call it correctly. Only the error/not-found behavior and the both-identifiers case are 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 coverage is 100% and both parameters carry examples, so the baseline is 3. The description adds the important or-relationship ("Pass url or slug"), clarifying that only one identifier is needed even though the schema marks neither as required. It does not state what happens if both are supplied or if the article is not found.

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?

"Get one Christian Pure article by its link or slug" gives a specific verb and resource, and the description enumerates the returned fields (title, excerpt, summary points, topics, image, dates). It also contrasts with searching via "look closer at a search result", so an agent can distinguish it from search_articles.

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?

"Use it when someone shares a christianpure.com link, or to look closer at a search result" gives concrete triggering contexts and implicitly routes discovery to the search tool. It stops short of naming search_articles as the alternative for keyword lookup, so the when-not guidance is only implied.

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