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

Annotations already declare readOnlyHint: true, so the read-only nature is covered. The description adds value by disclosing the full scope of returned data (7-day and all-time metrics, lifetime totals, top groups). It does not mention rate limits or side effects, but these are unlikely for a read-only aggregate tool.

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 two sentences, front-loaded with the core purpose and followed by a helpful disambiguation. Every phrase adds information without redundancy.

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?

Given the absence of parameters and the existence of an output schema, the description fully covers what the tool does and when to use it. It lists all data categories, mentions timeframes, and provides guidance relative to siblings, making it complete for an agent to invoke correctly.

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 has zero parameters, so the schema coverage is effectively 100%. Baseline for 0 params is 4. The description adds no parameter-specific semantics because none are needed.

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 the tool's purpose: retrieving network-wide numbers across all public Telegram groups tracked by Limzo, with a specific list of metrics (group count, messages, active users, etc.). It explicitly contrasts with list_groups for finding specific groups, distinguishing it from the sibling tool.

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 provides explicit usage guidance: "For finding a specific group, prefer list_groups." This indicates when not to use this tool and suggests an alternative. The network-wide scope also implicitly separates it from get_group_stats.

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