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

With no annotations, the description carries the full burden and does so: it discloses the precondition (recipient has not seen the handoff), the exact failure signal (handoff_already_seen), and the mandated recovery behavior (tell the user, then use amend_handoff if they agree). This is the behavioral context an agent cannot infer from the schema.

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 core action, then the precondition, then the failure path and alternative. Every sentence carries actionable information; nothing is redundant filler.

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?

For a mutation tool with no annotations and no output schema, the description covers purpose, preconditions, error behavior, fallback tool, and parameter intent. An agent has everything needed to invoke it correctly or route away when it will fail.

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 50% (title and handoffId have no schema descriptions), so the description must compensate, and it does: it clarifies that handoffId and key are alternatives, that title and/or body must accompany them, and that body is the full replacement text. Minor gap: it does not state that the parameters are technically optional in 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 ('Edit the title and/or body of a handoff YOU sent, in place') and scopes it to handoffs the caller authored. It is immediately distinguishable from amend_handoff, which it names as the alternative.

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 when-to-use ('Only call this when the user asks you to fix it'), an explicit when-not (only while the recipient has not seen it; addressed handoffs only), and names the alternative (amend_handoff) with the condition that selects it. It even forbids silently switching, which is unusually complete routing guidance.

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