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

Annotations already declare destructiveHint=true, so the description's added value is the conflict behavior ('Fails with conflict once the decision is settled') and the possibility of a `needs_confirmation` return, which the agent must handle. It does not spell out that field overwrites are irreversible, so it stops short of a 5.

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 dense sentences, each carrying distinct information (capabilities, guardrail, failure modes), with the core capability front-loaded. No filler or restatement of the tool name.

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?

There is no output schema, and the description covers the two return-path facts an agent needs (conflict on settled decisions, `needs_confirmation` envelope, which pairs with the approvalId parameter). It omits the workspace-token requirement, but that is already documented in the schema.

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?

With 13 parameters and only 46% schema description coverage, the description partly compensates: it maps dueOn to move, title to rename, url to link, status to the three enum values, and adds the non-obvious 'null clears' rule for ownerUserId. Only `note` and `itemId` are left undocumented in both places, so the compensation is incomplete but substantial.

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?

Opens with a specific verb+resource ('Edits one plan item') and enumerates the exact mutations supported (move via dueOn, rename, re-own, attach link, set status). It is trivially distinguishable from siblings ledger_plan_add, ledger_plan_delete, and ledger_plan_list.

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 a real precondition ('while its decision is open') and a substantive when-to-use rule ('Mark done only when the user says it shipped; a link alone doesn't mean done'). It never names a sibling tool as the alternative, so it falls short of a 5.

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