handoff_cancel

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

With no annotations, the description carries the burden and does well: it discloses the creator-only authorization requirement, the state precondition (OPEN only), and that strict-mode trust requires passing session creds. It omits failure behavior and whether cancellation is reversible, keeping it from 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?

Extremely front-loaded and dense: state transition, purpose, precondition, and auth note in three short clauses. The telegraphic style is efficient, though the clipped phrasing slightly risks ambiguity.

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?

Output schema exists so return values need no explanation. For a mutating, auth-sensitive tool the description covers the state constraint, authorization model, and strict-mode requirement adequately, leaving only edge-case failure behavior unstated.

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 100%, so the schema already documents agent_id, handoff_id, session_id, and session_secret in detail. The description reinforces the creator constraint and strict-mode credential requirement, but adds little syntax or format detail beyond the schema, matching the baseline 3.

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 with an explicit state transition ('OPEN -> CANCELLED') and a concrete purpose ('retract a handoff nobody should take'). An agent can distinguish it from handoff_reject and handoff_complete from the description alone.

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 clear when-to-use context with a concrete example ('a pool target matching zero agents') and a precondition ('Only OPEN handoffs cancel'). It does not explicitly name the alternative tools (reject/complete) or when NOT to cancel, so it stops 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.