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

With no annotations, the description carries full responsibility for behavioral disclosure. It reveals state persistence location, return fields including is_first_check and error, and the notification action. It does not cover failure modes or rate limits, but the core behavior is transparent enough.

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 extremely concise and front-loaded with the primary purpose. Each line adds value: state path, return format, and error field. No fluff or repetition exists.

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?

Although an output schema exists (covering return values), the description lacks essential invocation context: the role of selector and the behavior when chat_id is defaulted. An agent cannot determine how to use the selector parameter or what happens without a chat_id, leaving the tool incompletely specified for correct use.

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 0%, so the description must compensate for all parameter meaning. It only indirectly references the URL and Telegram notification (implying chat_id), but the selector parameter is entirely unexplained. This leaves a significant semantic gap for a required workflow.

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 states a specific verb ('Check'), a clear resource ('URL'), and the full behavior (persist hash, notify on change). It clearly distinguishes this from sibling tools like telegram_poll or file_convert, as it is specifically a URL-change monitor.

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 usage is implied through the description ('Check URL for changes; persist hash; notify Telegram on change'), but no explicit when-to-use or alternative guidance is given. It does not explain when to set chat_id or selector, which are needed for correct invocation in different scenarios.

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