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

Annotations already cover readOnly/idempotent/destructive, and the description goes well beyond them: it discloses an auth requirement, that alert error text is omitted, that missing fields mean 'not recorded', and how untrusted_fields flags data LastPing did not write (job output, exporter data, user names). That output-provenance disclosure is exactly the kind of behavioral context an agent can't 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?

The auth prerequisite is front-loaded, followed by purpose then edge-case semantics, so information is ordered by importance. It is dense and somewhat list-like, but nearly every clause carries non-obvious return-shape detail rather than filler.

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 must describe the return value, and it does: the full ordered event vocabulary, the run-id matching rule, the incident_opened fallback for body_excerpt/exit_code, omission semantics, and provenance fields. For a complex timeline tool this is complete enough to call 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?

Single parameter with 100% schema description coverage, so the schema already documents incident_id and its sources. The description adds no syntax or format detail for the parameter, which is the expected baseline 3 when structured data does the work.

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 first functional sentence states a precise verb and resource: 'Gets one incident and its ordered timeline.' The enumerated event types (run_started, step, incident_opened, etc.) and the note about run_* matching the opening run id make it clearly distinct from get_run, list_incidents, and add_incident_note without needing to open any 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?

Usage is only implied: it names an auth prerequisite ('Requires the read scope or higher') but never says when to reach for get_incident versus get_run or list_incidents, nor any exclusion. The incident_id provenance ('from list_incidents...') lives in the schema, not here. Adequate but leaves routing to inference.

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