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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds genuinely useful context beyond them: it is DB- and Redis-backed, costs no browser time, is safe to call while campaigns are running, and leads with BLOCKED status. It does not, however, describe the response shape or any rate/recency caveats.

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?

Front-loaded with the core purpose and the BLOCKED-status rationale early; every clause maps to a returned metric or a usage constraint. The metric enumeration is long but earns its place given there is no output schema, though the single run-on sentence is denser than ideal.

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 compensates by listing the report's contents in detail, plus notes on data source (DB/Redis, no browser), safety during running campaigns, the parallel Telegram delivery, and two sibling alternatives. An agent has everything needed to call it and interpret the result.

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% (both params documented, including the sessionId/sessionLabel relationship), so the schema carries the load. The description adds only a marginal note about defaulting to the default account and calling once per account, which is why the baseline 3 applies rather than higher.

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+resource+scope ('One account's end-of-day picture in a single call') and enumerates the exact metrics returned: invites sent, acceptances, messages, replies, backlogs, cleanup spend, failures, finished campaigns. It also explicitly distinguishes itself from li_account_activity and li_outreach_analytics.

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?

Explicit routing: 'For what is running right now use li_account_activity; for rates over time, li_outreach_analytics.' Also states the multi-account pattern ('call once per account for several') and that it defaults to the default account, so the agent knows both when and how to invoke it.

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