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

Well beyond the annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), it discloses the required scope bookings:write, that the first call is a no-op validation pass, that it rejects unknown fields by name, and that it returns a summary plus a confirm_token that must be echoed on the second call.

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?

Four short sentences, front-loaded with purpose then the permission requirement then the flow; no filler and the sequencing is easy to follow.

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 mutating, open-world tool with no output schema, it covers the critical contract: permissions, two-step confirmation, and the returned summary/confirm_token. It doesn't state what the second call ultimately produces (e.g. whether the request awaits the other party's approval or takes effect immediately), which is the remaining gap.

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 coverage is only 33%, and the description clarifies confirm_token usage (omit on first call, echo on second) — which the schema also documents — plus the rejection of fields the tool does not accept. It adds nothing about proposal_id or the units/meaning of minutes, leaving two required parameters unexplained in both places.

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 opens with a specific verb+resource ("Ask for more time") and immediately frames it as a two-call request flow, which cleanly separates it from accept_extension/decline_extension/cancel_extension siblings that act on an existing extension rather than asking for one.

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?

It gives strong in-tool usage guidance: call once to preview, show the summary to the person, and only call again after they agree. It doesn't say when to choose this over related siblings such as accept_extension or decline_extension, but the two-phase gating is explicit and unambiguous.

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