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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and a closed-world scope, so the safety profile is covered. The description adds genuinely non-redundant behavior: the tool returns a step-by-step guide rather than performing the action, and "opens nothing by itself," which prevents the agent from assuming a side effect occurred. The API/MCP-server note explains why a browser fallback is needed, though its dated parenthetical adds little.

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 actionable content is front-loaded in the first two sentences — what it returns and what it does not do — which is good structuring. But the lead clause ("from ChatGPT, Claude or any AI agent") and the trailing API note with a dated check are padding that does not change how an agent invokes the tool.

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, no output schema, and annotations covering safety, the description carries most of what an agent needs: it says the return value is procedural guidance and names the tools required to act on it. The main remaining gap is that it never states what the returned steps cover (e.g., which availability views or date ranges), leaving the agent to discover that downstream.

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 (empty object, additionalProperties false), so there is nothing for the description to disambiguate; the baseline of 4 applies. The description correctly implies no input is required by framing the output as a returned how-to.

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?

Names a specific verb and resource ("Check availability in the user's own Acuity Scheduling account") and then clarifies the actual mechanic: it "Returns how to do it in Acuity Scheduling step by step (screens, buttons, fields) and opens nothing by itself." That resolves what would otherwise be a misleading name. It does not differentiate against siblings such as acuity_scheduling_list_appointments or cotlet_app_guide, so it stops short of a 5.

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?

Provides a clear follow-on path — "then do it with the cotlet_browser_* tools in the user's Acuity Scheduling Cloud Browser" — which tells the agent this is a planning step in a two-phase workflow. However, it never states when to choose this over acuity_scheduling_list_appointments or cotlet_app_guide, nor any exclusions or prerequisites. Usage is implied by the workflow chain rather than stated as selection guidance.

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