update_conversation_messages

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

Annotations already flag destructiveHint=true and idempotentHint=false, but the description goes further: it names the exact storage key that gets overwritten (voiceglow/{agentId}/convos/{convoId}/convo/JSON_STRING), states that the whole transcript is replaced rather than merged, and enumerates which metadata fields are rewritten downstream. That is genuine disclosure beyond annotations.

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-loaded with the verb, the resource and the endpoint, and each following sentence covers a distinct concern (what is overwritten, downstream side effects, the required guard). The literal storage path is slightly redundant noise for an agent already given the schema, which keeps it from a 5.

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 destructive mutation with no output schema, the description covers the blast radius, the safety guard, and the side-effect fields, and annotations cover reversibility and openness. No annotation contradiction; nothing an agent needs in order to call this safely 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 schema already documents turns, agentId, convoId, lgMessages, confirmReplace and updateConversationMetadata. The description restates the turns semantics and the metadata side effects in prose, which is a mild reinforcement but adds no new syntax or format detail beyond the schema. Baseline 3 applies.

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?

Names a specific verb (Replace) and a specific resource (stored message turn history for a conversation), and anchors it to the exact endpoint PATCH /agents/{agentId}/convos/{convoId}/messages. This is clearly distinguishable from update_conversation, which the sibling list shows handles the conversation document rather than the transcript.

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?

Explains the operative condition (full replacement of history, hence confirmReplace must be true) and calls out the default metadata-refresh behavior. It stops short of explicitly naming update_conversation or update_conversation_note as alternatives for narrower edits, so the agent must infer that partial edits belong elsewhere.

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