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

The annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true and openWorldHint=false, and the description is consistent with them by saying it "opens nothing by itself." It adds useful context (returns screens/buttons/fields; no official API as of the dated check) but does not describe the shape of the returned guide, how the target account is bound, or what happens if no browser session exists. The extra context is real, though modest beyond the annotations.

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?

Front-loads the action and the key caveat ("opens nothing by itself") before the handoff instructions, so a skimming agent gets the critical fact first. The API-digest sentence is somewhat long and tangential, but it earns its place by pre-empting a wrong API attempt.

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 input schema, no output schema and no parameters, the description carries the burden and mostly meets it: what the tool does, what it returns, and what to do next. The remaining gap is that it never says how the Klean CRM account/session is resolved given zero parameters, which an agent may need before calling.

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 with additionalProperties=false, so there is nothing for the description to disambiguate. Baseline applies; the description does implicitly explain that account context comes from the user's own session rather than from inputs.

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 ("Send invoice in the user's own Klean CRM account") and then clarifies the real output: step-by-step instructions with screens, buttons and fields. The opening framing could mislead an agent into expecting an executed action, but the immediate correction ("opens nothing by itself") resolves it, so the tool's nature is discernible without opening a schema.

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 onward to the cotlet_browser_* tools and rules out the API path by stating Klean CRM publishes no API, webhooks or Zapier app. It stops short of naming a distinct sibling (e.g. cotlet_app_guide) as an alternative for non-browser guidance, but the when/when-not logic is clear for this tool's scope.

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