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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: it 'opens nothing by itself' and returns screens/buttons/fields, plus the note that Squire has no public API. It stops short of describing output format or failure modes, so a 3 is fair.

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?

The core instruction is front-loaded, but the second sentence is a run-on that mixes the return value, the no-side-effect guarantee, and the browser handoff. The closing line 'Squire's official API: Squire has no public API and no developer docs' is redundantly phrased and could be tightened.

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 parameters and no output schema, the description carries the burden of explaining what comes back, and it does ('how to do it in Squire step by step (screens, buttons, fields)'). It also explains the handoff to browser tools, leaving only minor gaps around what the step list looks like in practice.

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; baseline 4 applies. The description correctly implies no input is needed to retrieve the guidance.

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 ('List appointments in the user's own Squire account') and clarifies the actual output is step-by-step instructions rather than data. The dual nature (name implies listing, description says it returns a how-to guide) creates mild ambiguity against siblings like squire_list_clients, but the intent is still recoverable.

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 to the follow-up action: 'then do it with the cotlet_browser_* tools in the user's Squire Cloud Browser.' It gives clear context for the workflow but never states when NOT to use this tool or which sibling to prefer for a different appointment operation.

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