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

Annotations already cover write/destructive/open-world status, and the description adds non-obvious effects: the «edited» marker, immediate update on open screens, and that edits re-notify nobody, including added mentions. It omits whether prior content is recoverable, but that is a minor gap given annotation coverage.

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?

A single dense sentence front-loads the action, then layers UI and notification effects. It is compact, though the colon-chained clauses require a careful read.

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 full schema coverage and annotations supplying the safety profile, the description supplies the missing behavioral and precondition context. It is nearly complete, with only minor omissions such as history/reversibility.

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 body/chatId/messageId are already documented, including Markdown format and the 32 KB limit. The description adds no parameter-level detail beyond what the schema provides; baseline 3 is appropriate.

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 ('Change the words') and resource ('a message you wrote'), and distinguishes the operation from send/delete siblings by limiting it to one's own non-deleted message. An agent can identify the operation without opening the 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?

Provides clear preconditions — only your own message, not a deleted one — and frames it as the screen's Edit action, which implicitly separates it from send_chat_message and delete_chat_message. It does not explicitly name those alternatives, so it is not a 5.

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