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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, closed-world), so the description's job is to add return-content context. It does that by naming the exact channels returned (Telegram, e-mail) and that sending instructions are included — meaningful disclosure given there is no output schema.

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?

Very short and front-loaded: the returned content leads the sentence. The bilingual restatement is redundant for an English-speaking agent, but it is a minor tax rather than a structural flaw.

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 parameterless, read-only tool with no output schema, the description supplies what is otherwise missing — the shape of the response (contact channels plus message-sending guidance). Nothing an agent needs to invoke it correctly is absent.

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 tool takes zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. Schema coverage is 100% and additionalProperties is false, so no undocumented inputs can exist.

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 names a specific resource (the developer's Telegram and e-mail) and adds the scope of 'how to send a message', so an agent knows this is a static contact-info lookup. It stops short of explicitly distinguishing itself from get_about or send_message, which is the one thing that would make the boundary 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?

There is no statement of when to call this versus alternatives. The phrase 'how to send a message' hints at a relationship with the send_message sibling, but the description never says 'use this to learn the contact channel, then call send_message' — the routing is left entirely to inference.

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