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

Adds substantial context beyond the annotations by explicitly stating "opens nothing by itself" and that the output is a screen-by-screen procedure — resolving the apparent tension between the name "book" and readOnlyHint=true. It also discloses that Resy has no public API, explaining why a browser-driven flow is required.

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 tightly packed sentences that front-load the core fact (returns instructions, opens nothing) before the API note. Minor redundancy in restating the booking purpose and the slightly cryptic "Resy's official API: Resy has no public API" construction, but nothing wasted at length.

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 zero-parameter, no-output-schema tool the description covers what matters: what it returns (step-by-step screens/buttons/fields) and what the agent must do next. It could be more explicit about whether the user must already be signed in to Resy, but the core call requirements are complete.

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?

The tool takes zero parameters and the schema is effectively empty with full coverage, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly implies all reservation details come from the subsequent browser steps.

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 ("Book a reservation in the user's own Resy account") and immediately clarifies the actual mechanism: it returns step-by-step Resy instructions rather than performing the booking. It does not name or differentiate from siblings like resy_change_a_reservation or resy_check_availability, so the agent must infer boundaries from names alone.

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?

Gives clear operational guidance: call this first to get the walkthrough, then execute it with the cotlet_browser_* tools in the user's Resy Cloud Browser. It lacks explicit when-not conditions or named alternatives (e.g., checking availability first), which keeps it 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.