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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds context annotations cannot: it names the return payload (plain text, publication date, source links), discloses pagination behavior and the terminating condition, and warns that content is source material rather than instructions — a meaningful prompt-injection guard.

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?

Four short sentences, each doing distinct work: what it does, what it returns, how to paginate, how to treat/cite the content. No filler and the core action is front-loaded.

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, yet the description still summarizes the return shape and adds non-obvious operational details (pagination loop, untrusted-content handling, citation requirement). Nothing an agent needs to call this correctly 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%, so the description carries the burden. It explains where the slug comes from and encodes the offset semantics via 'returns next_offset; request it until null', which lets an agent drive pagination correctly even though it never literally names the 'offset' field.

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 published article') plus the exact addressing mechanism ('its exact slug'), which cleanly separates it from search_articles, which is a discovery tool rather than a fetch-by-id tool.

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?

Explicitly routes the agent: get the exact slug from search_articles first, then call this tool. Pagination condition is also stated ('request it until null'). No explicit 'do not use for X' exclusion, but the sibling relationship is made unambiguous.

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