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

Beyond the readOnlyHint and idempotentHint annotations, the description adds meaningful behavioral detail: raw events are returned newest-first, a range summary appears on the first page, results are bounded by retention, and pagination uses next_cursor until exhausted. This is valuable runtime context that annotations do not provide.

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 compact and front-loaded: the core behavior is in the first sentence, followed by retention and pagination notes. The phrase 'Page with next_cursor until exhausted is true' is grammatically awkward but adds necessary loop-termination information without waste.

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, idempotent tool with no output schema, the description covers the key operational details: filtering, ordering, first-page summary, retention, and pagination. It does not describe the exact result shape or explicitly route away from sibling tools, but those gaps are minor given the annotations and schema coverage.

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 high (83%), with org, since, user_ids, and cursor already documented. The tool description adds little parameter-level meaning beyond what the schema already says; the 'given identifiers' and 'next_cursor' references mirror the schema descriptions. It also does not compensate for the undocumented 'limit' parameter.

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 identifies the resource as 'the timeline of one customer' and the selection mechanism as 'every raw event whose user_id matches any of the given identifiers.' It also specifies ordering (newest first), which distinguishes it from sibling tools like get_event or event_stats without needing to name them.

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 use context is clear: this is the tool for retrieving a single customer's raw event stream by user_id. It does not explicitly compare itself to alternatives like search_events or state when not to use it, but the purpose is specific enough that an agent can infer when it applies.

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