retract

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

Goes well beyond the annotations: soft-delete mechanics ('nothing is deleted, and history still walks it'), the scope of suppression ('session start, the moment of action, lookup'), replica behavior ('on a replica this queues instead of writing') with an explicit non-error clarification, and the refusal path. The 'nothing is deleted' wording is a mechanistic nuance of destructiveHint=true rather than a contradiction, since liveness is irreversibly removed.

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?

Front-loads the lane and the core distinction before edge cases, and every clause carries information about behavior, error handling, or return text. Slightly dense with stacked parentheticals ('queued for the main machine', the reply template), which costs a little readability against a five.

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 supplies the return contract ('retracted <id> (<reason>) (event seq N)', or the refusal text), covers the distributed-replica edge case, and defines the retraction semantics end to end. 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 coverage is 100%, so the baseline is 3; the description lifts it by restating the hard rejection condition operationally ('A reason is required; a blank one is refused'), which tells the agent a blank value produces a refusal rather than a silent success. It adds no new format or syntax detail for 'id' beyond the schema.

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 ('removes an item that is simply WRONG or no longer applies') and immediately scopes it against the closest sibling by naming the alternative ('Use revise instead when the item merely changed'). An agent can distinguish retract from revise, mark, and shelve 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?

Explicit when-to-use ('simply WRONG or no longer applies'), explicit when-not and alternative ('Use revise instead when the item merely changed'), and a further rule for a related case ('Bringing the fact back later is a fresh remember, never a revise of the tombstone'). Preconditions (reason required, blank refused) are stated up front.

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