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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's value is in disclosing the returned payload — `summary`, `author`, `language` — and that for non-priced kinds these fields constitute the entry's actual content. It does not mention behavior for an invalid or missing entryId, which is the one 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?

Purpose is front-loaded and the contrast with the list tool follows immediately; every clause carries information. The emphasis on "these two fields ARE the entry's content" is slightly repetitive but justified given how easily an agent would otherwise skip this call.

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?

With no output schema, the description carries the burden of explaining return values and does so concretely, including the semantic distinction between list and full-read results. For a one-parameter read tool, nothing needed to call it 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 coverage is 100% for the single `entryId` parameter, so the schema already documents it. The description only indirectly adds provenance (the ID comes from list_source_entries), which is marginal beyond the baseline.

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 one item in full") and immediately contrasts the scope with list_source_entries, noting this returns prose the list omits. An agent can distinguish it from get_entry_changes/get_entry_updates and list_source_entries without opening any 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?

Gives an explicit triggering condition and the alternative that precedes it: "Use it after list_source_entries names an entry worth reading." That routes the agent through the correct workflow rather than guessing which entry-reading sibling to call.

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