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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior. The description adds real context beyond that: the corpus is public channels tracked by Catalogue App with 1.5M+ entries, and the result fields are enumerated. It omits pagination and how the 15/50 limit cap behaves, which keeps it from 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?

Three short sentences, front-loaded with scope and size of corpus, then filtering, then return fields. No filler or redundant restatement of the 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?

With no output schema, the description usefully lists return fields (@username, title, kind, subscriber count, links), so an agent knows what comes back. The gap is result-set behavior: default 15 / max 50 limit semantics and whether results are ranked or truncated are unaddressed.

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 coverage is 50%, so the schema documents query and kind but leaves min_subscribers and limit bare. The description's 'filter by kind and size' maps loosely onto kind and min_subscribers, giving a hint about the size filter, but it never explains limit or the enum value 'room'. Baseline 3 given partial compensation.

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?

Specific verb plus resource with scope: 'Search 1.5M+ public Telegram channels, group chats and bots tracked by Catalogue App.' The resource is clearly distinct from the sibling search_apps and search_packs without needing to open any schema.

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 description implies usage context ('Filter by kind and size') but never states when to prefer this tool over siblings like search_packs or search_apps, nor any exclusions such as private or untracked chats. The purpose makes the intent inferable, but no explicit when/when-not guidance is given.

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