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

With readOnlyHint and idempotentHint already declared, the description adds the crucial context that the tool "opens nothing by itself" and only returns screens, buttons and fields — resolving the mismatch between the mutating name and the read-only annotations. It stops short of describing how large or structured the returned guide is.

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 purpose and the no-side-effect disclaimer are front-loaded and worth their space. The trailing sentence about Aircall's public REST API and a beta official MCP server, complete with a future-dated check stamp, does not help an agent select or invoke this tool and dilutes the message.

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 guidance tool, the description covers the two things that matter: what comes back (a step-by-step walkthrough) and that nothing is executed. It leaves a small gap by not explaining how the target call is identified, since no parameter can carry that.

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 schema baseline of 4 applies and there is no parameter meaning the description needs to recover.

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 (add call note in Aircall) and the second immediately redefines it as a step-by-step guide rather than an action. That reframing is essential given the tool name implies a mutation, but the description never positions itself against the overlapping 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?

It does hand off the actual work explicitly — "then do it with the cotlet_browser_* tools in the user's Aircall Cloud Browser" — which is a usable when/how hint. However, there is no when-NOT guidance, no condition separating it from cotlet_app_guide, and no statement about what an agent should do if the user has no specific call in mind.

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