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

Annotations already declare the safe-read profile (readOnlyHint, idempotentHint, non-destructive), and the description goes well beyond them: the slotToken is signed, expires in about 30 minutes, must be passed back unedited, must not be reused across venues. That is exactly the operational behavior an agent needs and cannot 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?

Front-loaded with purpose and scope, then token semantics, then the empty-result edge case — a logical ordering with no filler. Slightly long and a couple of clauses ('never edited, and never reuse one from a different venue') repeat the same constraint, costing a point.

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 still explains the return shape (an `at` label and a `slotToken`), the meaning of an empty `times` array, and the token's lifetime — enough for an agent to call the tool and correctly hand off to a booking tool. Nothing material is missing.

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%, so the schema already documents venue, partySize, days, and from in detail (including rejected formats). The description reinforces 'one party size' and 'up to two weeks' but adds no syntax or format detail 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 and resource ('free table times at one restaurant or venue'), plus the scope constraints of one party size and up to two weeks. It explicitly names the sibling it is not (find_appointment_times for salons/clinics), so an agent can route correctly without opening a 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?

Explicitly gives the alternative tool and the condition that selects it ('Use find_appointment_times for a salon or clinic instead'), and bounds the search domain to one venue, one party size, and up to two weeks. The empty-result guidance ('usually means closed or fully booked', large parties may be taken by phone) tells the agent how to interpret and act on outcomes.

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