messages_update

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the safety profile is partly covered structurally. The description adds genuine context beyond that: it warns that the action reaches other people and can delete or redirect data, and mandates user confirmation. It stops short of noting edit-window limits or permission requirements.

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?

Purpose is front-loaded and the piece is short. The middle sentence is a garbled run-on whose subject is unclear ("Reaches other people on the platform, deletes, or redirects data"), and the trailing transport-metadata line is operational noise for a tool-selection decision.

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?

No output schema exists and all four required parameters are described only by example values in the schema. The description covers the risk/confirmation dimension but leaves the agent without any guidance on what the IDs mean or whether content replaces existing text. For a mutation tool this is materially incomplete.

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 0% with 4 required parameters (chatId, channelId, messageId, content). The word "text" loosely maps to content, but the three ID parameters that identify the target message are entirely undocumented in both the schema and the description. With low coverage the description should compensate and does not.

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?

The opening sentence states a specific verb+resource: "Edit a sent message's text." An agent can distinguish this from siblings like messages_reply, messages_send, or messages_delete, but the description never names those siblings or states the boundary explicitly.

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?

It gives a strong conduct instruction — "say exactly what will happen and get the user's confirmation first" — which sets usage expectations for a destructive operation. However, it never says when to choose this over alternatives (e.g. messages_reply for new content vs messages_update for editing), leaving selection to inference.

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