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

Annotations already mark the tool as readOnly, openWorld, idempotent, and non-destructive. The description adds valuable context about the 'semantic web index scoped to t.me' and the 'discovery' nature, warning that results may be limited. No contradiction; it goes beyond annotations by explaining the index scope and historical nature.

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?

Two focused sentences: first states purpose and scope, second gives crucial usage guidance and sibling reference. No fluff, front-loaded with the verb and resource, and earns its place with actionable advice.

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 search tool with 3 parameters and no output schema, the description covers scope, limitations, and integration with glim_telegram_get. However, it doesn't specify the structure of returned results (e.g., whether it returns handles, channel names, or how many). Annotations and format parameter partially compensate, but a brief mention of result contents would improve completeness.

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?

Input schema already provides 100% coverage with clear descriptions for query, kind, and format. The description adds context for the overall discovery purpose and relationship to get, but does not explain parameter semantics beyond what the schema already states. Schema carries the load, so a baseline of 3 is appropriate.

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 it 'Search Telegram' and details two specific discovery modes: channel directory lookup and indexed public post/channel pages. It distinguishes from siblings by noting this is a discovery tool, explicitly contrasting with glim_telegram_get for live posts/history.

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?

Provides explicit guidance on when to use this tool ('find the right channel here') and when to use the alternative glim_telegram_get for live posts or in-channel search. The tip about Telegram's lack of global text search frames the tool as a discovery starting point.

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