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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral content beyond that: the data is daily-granular and the timeline includes deployment markers tied to merges, which tells the agent what the output will let it reason about.

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 what the tool returns, then a compact set of example prompts. Every sentence earns its place; no filler or restatement of the title.

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 analytics tool with a fully documented schema and no output schema, the description covers what is returned (daily scores, deployment markers) and the questions it answers. An agent has enough to select and call it 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?

Schema description coverage is 100%, with defaults and max documented for 'days' and the superadmin-only note on 'customerId'. The description only restates 'over a date range' and adds no format or scoping nuance beyond the schema, so the baseline 3 applies.

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 ('daily score timeline for an agent over a date range') plus an extra distinguishing feature (deployment markers for merged PRs). It is clearly an agent-scoped read, which implicitly distinguishes it from the fleet-level sibling get_fleet_timeline, though it never names that sibling.

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 three quoted example questions ('did overall performance improve after our fixes?', 'show me the score trend') give concrete context for when to reach for this tool. There is no explicit when-not guidance or named alternative (e.g. get_deployment_impact, get_fleet_timeline), so it stops short of a 5.

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