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

Annotations already cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), so the description's real contribution is domain behavior: this action reserves exclusivity over the body for that window, blocking other renters. That is exactly the kind of non-obvious consequence an agent needs; it doesn't discuss failure modes (window already taken, inquiry expired), which keeps it below a 5.

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, precondition first, mechanism second, follow-up last – well front-loaded with no filler. Slightly dense domain jargon ("body", "promise of lease") assumes prior context, but nothing is redundant.

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 two-parameter mutation with no output schema, the description covers the actor restriction, the required inquiry state, what gets created, and how to consume the result (promise_id via request_lease). Missing only error/edge-case behavior, which is a modest gap given the annotation 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 coverage is 50% – window_index is already documented as an index into offered_windows, and the description only restates "pick one offered window by window_index." inquiry_id is undocumented in both schema and description beyond the implication that the inquiry must be in an offered state, so the description adds little beyond the structured fields.

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 action (accept one offered window) plus its consequence (creates a promise of lease) and the exclusivity guarantee over the body's window. It also positions the tool relative to the sibling request_lease, so an agent can tell these two apart without opening either 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?

"Renter only, inquiry must be offered" gives explicit preconditions, and "Redeem it with request_lease and promise_id when the window opens" names the follow-up tool and its trigger. It stops short of saying what to do when the inquiry is not offered (e.g., use create_inquiry or cancel_inquiry instead), so it is strong but not fully exhaustive.

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