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

Annotations establish the read-only, non-destructive, closed-world profile, and the description goes well beyond that: 13-month summary retention, 30-day username/comment retention, the plan_limit failure cause with a pointer to get_account, why an already-in-flight commenter is omitted, and an explicit prompt-injection caution about treating comment text as data. That is rich behavioral context an agent could not get from structured fields.

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?

Purpose is front-loaded and the prose is information-dense, with no filler sentences. It is on the long side because it enumerates every summary counter and stage name, some of which leans toward output-schema territory, but each enumeration carries domain meaning.

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 complex, retention-bounded analytics tool with an output schema, the description covers what matters: what the totals and per-entry stages mean, failure causes, data lifetimes, and a safety note on untrusted comment content. Nothing an agent needs to call or interpret it correctly is missing.

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% (limit, before, automation_id are all documented in the schema), so the baseline is 3. The description implies newest-first ordering but adds no syntax, format, or pagination detail beyond what the schema already provides.

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 opening line states a specific verb and resource: it reports who an automation DMed and how far each recipient progressed, ordered newest first with totals. This is unambiguous and an agent can distinguish it from list_automations or get_account without opening a 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 makes the usage implicitly clear (inspect per-recipient DM progress for a given automation), but it never states when to reach for this tool versus siblings, nor any exclusions or prerequisites. Usage must be inferred from the content it promises to return.

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