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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true and openWorldHint=false; the description reinforces this by saying it 'opens nothing by itself' and only returns a guide, which explains why a tool named 'update' is non-destructive. It also adds plan-level context (REST API only on Plus/Premium, official MCP servers cannot work the inbox). The dated 'checked 17 Oct 2026' claim is unverifiable noise, and the return format is only loosely characterized.

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?

Purpose and behavior are front-loaded in the first two sentences, which is good, but the closing sentence about Tidio's official API, plan tiers, and a dated check is tangential to invoking this tool and lengthens the definition without helping selection. The core message could be delivered in half the words.

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 definition supplies what an agent needs: what the call returns (step-by-step screens, buttons, fields), that it changes nothing, and which tools carry out the actual change. The only gap is a precise description of the return payload's structure, which the description gestures at rather than specifies.

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, so there is nothing for the description to disambiguate and the schema is fully covered. Baseline for a parameterless tool applies; the description correctly avoids inventing inputs.

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 first sentence names a specific verb and resource (update contact properties in the user's own Tidio account), and the second sentence corrects the impression of a direct mutation by stating the tool actually returns step-by-step instructions. That hand-off framing distinguishes it from sibling tools like tidio_update_ticket or the cotlet_browser_* family. The initial 'update' phrasing is momentarily ambiguous, but the description resolves it in place.

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 explicit workflow guidance: call this to get the screens/buttons/fields, then perform the action with cotlet_browser_* tools in the user's Tidio Cloud Browser. It does not state when this tool should be avoided (e.g., if the user has a Plus/Premium API path), but the routing to the browser tools is concrete enough to select correctly.

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