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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), but the description adds real interpretive context: matches carry custody model and incident history, and it explicitly warns that a match is not a safety rating and that 'unknown' is not proof of a scam. That caveat meaningfully shapes how an agent should report results. It does not describe response shape or multi-match behavior, keeping it short of a 5.

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 action and scope of the lookup are front-loaded in the opening clause, followed by the outcome taxonomy and a short interpretation caveat. Three sentences, none redundant, with no restatement of the tool name.

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?

There is no output schema, so the description must convey what comes back, and it largely does by defining the result categories and noting that matches include custody model and incident history. It stops short of describing how multiple matches, partial matches, or confidence are represented, which an agent would benefit from for a single free-text lookup.

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% and the single param already documents accepted forms (@handle, t.me/ link, tg://resolve link), so the description is not required to carry parameter meaning. It adds no syntax, normalization, or constraint detail beyond the schema, which is the expected baseline when the schema does the heavy lifting.

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 (check a Telegram @handle / t.me link) and scopes it to the domain concept that matters: whether it is an official handle, a known impersonator, a look-alike, or unlisted. Sibling tools check_bot and check_website address different artifacts, and the description makes the Telegram-specific scope unmistakable.

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 four possible outcomes are enumerated, which tells the agent when this tool is the right lookup and what a given answer means. However, it never explicitly names an alternative (e.g. check_bot for the bot itself, check_website for the site) or states a when-not-to-use condition, so selection guidance rests on inference.

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