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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile needs no restating. The description earns credit for two pieces of context the annotations lack — result ordering ('newest first') and a 90-day retention window — but says nothing about event volume, pagination behavior beyond the schema, or what an event record contains.

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 short sentences with zero filler; the ordering and the retention limit are front-loaded and each clause contributes distinct information. Nothing could be removed without losing a fact.

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 read-only, paginated list tool whose parameters are fully described in the schema and whose safety is covered by annotations, the description supplies the two things an agent could not infer: 90-day retention and newest-first ordering. The remaining gap — no hint at the shape of an event record and no output schema — is minor but real.

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%, so every parameter (limit, cursor, copier_id, follower_id) is already documented in the schema, and the baseline is 3. The description adds only the framing that events apply to 'the copier's followers', which loosely motivates follower_id without adding filter syntax or semantics beyond the schema.

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 identifies a specific resource — copy events for a copier's followers — and states their ordering ('newest first'), which separates it from siblings like list_followers or get_copier. It stops short of an explicit verb ('list/return'), describing the content ('What the copier engine did, or decided not to do') rather than the action, so it is clear but not maximally crisp.

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?

Usage is only implied: reading 'what the copier engine did' suggests an audit/debugging context, but the description never says when to call this versus list_followers or get_copier, nor does it name any alternative. No exclusions or prerequisites are given.

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