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

Annotations already declare readOnlyHint=true, openWorldHint=false, idempotentHint=true and destructiveHint=false, so the safety bar is low. The description still adds real context beyond those fields: 'opens nothing by itself' and the fact that the response is procedural guidance ('screens, buttons, fields') rather than call data, which fundamentally changes how an agent should treat the output.

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 paragraph is compact and front-loads the 'returns how-to, not data' fact, but the trailing sentence about Aircall's official REST API and beta MCP server (with a future 'checked 23 Oct 2026' stamp) is filler that does not help selection or invocation and dilutes the actionable content.

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, read-only guide tool with no output schema, the essentials are mostly covered: what comes back and which tools execute the action. It stops short of explaining how the returned steps map onto the specific browser tools (navigate, find, click) or what to do if the Aircall session is not authenticated.

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 the baseline is 4 and there is nothing for the description to disambiguate. No misleading parameter language is present.

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 description eventually clarifies that the tool returns step-by-step instructions rather than data, but this conflicts with the name/title 'List calls' and with the first sentence's framing ('List calls in the user's own Aircall account'), so an agent must read the whole description to learn the real output. It does name the execution path (cotlet_browser_* tools), which is helpful, but it never distinguishes itself from the similar-looking cotlet_app_guide sibling.

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?

There is an implied workflow: get the steps here, then act via cotlet_browser_* tools. However, no guidance is given on when to pick this over cotlet_app_guide, cotlet_get_call, or aircall_get_call_summary, and no prerequisite (e.g., the Aircall Cloud Browser session needing to be open) is stated.

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