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

The annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered; the description reinforces this with 'Read-only' without contradicting it. It adds genuinely useful behavior beyond the annotations: a cap of up to 3 windows, that windows are filtered by the task's estimated duration, and that timestamps are ISO-8601 start/end pairs.

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?

Three short sentences, front-loaded with the action and scope, followed by return shape, then the safety/usage note. Every sentence carries distinct information and there is no 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 correctly carries the burden of describing returns (up to 3 windows with ISO-8601 start/end). For a one-parameter read tool this is nearly complete, missing only edge-case behavior when no suitable window exists.

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 0%, so the single task_id parameter has no documented meaning in the schema itself. The description partially compensates by explaining that the task supplies the estimated duration and that the owner's calendar drives the lookup, but it never states what task_id is or what happens with an invalid or ownerless task.

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 gives a specific verb and resource (suggest free time slots for a task) and scopes it to the owner's calendar and the task's estimated duration. It clearly distinguishes itself from a plain scheduling write, though it never names or distinguishes itself from similar read siblings such as get_free_windows or get_busy_blocks.

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?

'Read-only — use it to reason before proposing a scheduled time' gives an explicit usage moment and implicitly routes the agent to a scheduling action afterward. It stops short of stating when not to use it, or which sibling to prefer for raw free/busy data, so it falls 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.