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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=true, so the safety profile is covered. The description adds the useful context that delivery goes through the user's own bot and is limited to reachable chats, but says nothing about rate limits, per-chat throttling, or what happens on send failure — extra context that would matter for a messaging mutation.

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 front-loaded sentence that carries the action, the channel, and the destination constraint with no filler. Nothing could be removed without losing information.

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 simple two-parameter, fully documented tool with no output schema, the description covers the essentials and supplies the bot-reachability constraint the schema does not. It falls short of complete only on delivery behavior and limits, which rarely block a correct invocation.

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 100%: 'text' documents the 1-4096 character bound and 'chat_id' documents the numeric-or-@username form plus where to obtain it. The description adds nothing beyond the schema for either parameter, so the 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?

States a specific verb and resource ('Send a text message ... to a chat') and scopes it to the agent's own Telegram bot, clarifying the delivery channel. It does not distinguish itself from the parallel sibling beeper_send_message, so an agent with both tools has no routing cue, but the action itself is unambiguous.

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?

The parenthetical states an important prerequisite: the destination must be a user who has DM'd the bot or a group/channel the bot is in. That is real usage context (an agent cannot message arbitrary users). However, it never names an alternative channel tool (beeper_send_message, typefully_post) or states when not to use this.

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