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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds the important detail that it is a guidance-only tool that performs no action and hands off to the browser tools, which is real added context. The closing paragraph about SimpleTexting's REST API and lack of an official MCP server is unrelated to invoking this tool and dilutes the behavioral signal.

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 first sentence front-loads useful scope, but the second is a run-on that packs return content, side-effect disclaimer and handoff into one clause chain. The third sentence is off-topic promotional/API trivia, including a future date ('checked 23 Oct 2026'), and does not help the agent act.

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 saying what comes back and what to do next, and it does both at a high level. It never clarifies what 'keywords' means in SimpleTexting or how the returned steps relate to the sibling list tools, leaving a modest gap.

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?

There are zero parameters, so there is nothing for the description to disambiguate and the schema is trivially complete. Baseline 4 applies; the description neither helps nor harms here.

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 does say the tool returns a step-by-step guide (screens, buttons, fields) for listing keywords rather than the keyword data itself, which is useful clarification. But the name/title 'List keywords' implies data retrieval, and the mismatch is never resolved explicitly, so an agent may expect a keyword list back.

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 states that this tool 'opens nothing by itself' and that the actual action must be performed with the cotlet_browser_* tools, which is genuine routing guidance. It gives no condition for choosing this over sibling tools like simpletexting_list_segments or cotlet_app_guide, so the 'when not to use' side is missing.

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