set_typing

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

Annotations cover readOnly=false, idempotent=false, destructive=false. The description adds behavioral context: how the signal is temporary, can be cancelled via action='cancel', and delay_seconds controls duration. This goes beyond the structured 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?

The description is short and front-loaded with the main purpose, followed by a clean bullet-style list of arguments. No redundant or filler sentences.

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?

Given the tool's simplicity and the presence of an output schema, the description covers all necessary information: what, where, and how. Minor gap: no mention of prerequisites (e.g., being a chat member) but that is not essential for this kind of tool.

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?

The schema has no parameter descriptions (0% coverage), so the description carries the full burden. It explains chat (id or @username), action (typing, record-audio, cancel, etc.), and delay_seconds (how long to hold status), adding meaning beyond the enum and defaults.

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 description clearly states the tool sends an activity signal (typing/recording/sending) to a chat, using a specific verb and resource. It distinguishes itself from siblings like send_message (actual message) and set_online (online status).

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?

Usage is implicit: the tool is for showing chat activity status. It does not explicitly mention when not to use it or name alternatives, but the purpose is clear enough for an agent to infer appropriate use.

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