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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description's field list and 'live bookable timeslots' phrase add modest behavioral context (real-time availability), but it discloses no auth requirements, rate limits, or caching/freshness specifics beyond that.

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?

Two tight sentences: the first front-loads what the tool returns, the second handles sibling routing. No filler, and the most important information (purpose) leads.

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?

An output schema exists, so return values needn't be spelled out, and annotations cover safety. For a 3-param read tool the description is nearly complete, though it leaves optional-param behavior (e.g., that omitting date_time defaults to now for timeslots) to the schema.

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 date_time, party_size and restaurant_id are already documented. The description references 'a date and party size' for timeslots, which contextualizes those two optional params but adds no format or default detail beyond the schema, making the baseline 3 appropriate.

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 ('Fetch') and resource ('OpenTable restaurant profile') and enumerates the returned payload (location, cuisines, hours, price band, review summary, live timeslots). It also names the sibling tools it is distinct from (menus, reviews, search), so an agent can disambiguate without opening any 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 routes the agent: use opentable_search to find a restaurant, opentable_restaurant_menus for menus, opentable_restaurant_reviews for reviews. This implies the prerequisite (having a restaurant_id) and the correct alternative for each adjacent need. It stops short of stating 'when not to use' in absolute terms, keeping it below a 5.

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