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

With no annotations, the description carries the full burden and does disclose two behavioral facts: 'Nothing is hidden' implies neither thread is removed or hidden, and the backer/steward threshold is a gating rule. It omits permissions, idempotency, reversibility, and what happens if the link already exists.

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, purpose front-loaded, no filler. The terse gating phrase is efficient though under-explained.

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?

No output schema and no annotations, so the description must cover behavior and parameters; it leaves both parameter meanings and permission/return behavior unexplained. It is not sufficient for an agent to invoke this confidently.

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 0% and neither 'thread_id' nor the oddly named 'of' is explained. The phrase 'a thread to an earlier one it duplicates' only weakly implies thread_id is the duplicate and 'of' is the original, leaving real ambiguity.

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 states a specific verb ('cross-link') and resource ('a thread to an earlier one it duplicates'), which clearly separates it from siblings like merge_tags or related_by_citation. However, it doesn't name an alternative or clarify which of the two threads each parameter represents.

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?

'Live at 2 backers or a steward' hints at a gating condition, but it is cryptically phrased and never states when to use this tool versus alternatives. No exclusions or sibling routing are given.

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