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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the baseline is low; the description still adds real context by stating it performs no action itself, describes the shape of what it returns (screens, buttons, fields), and notes that Findymail has a REST API but no first-party MCP server. That last point usefully explains why browser automation is the path.

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 behavior is front-loaded, but the second half is a dense run-on that mixes operating instructions, a browser-tool dependency, and an API/MCP availability aside. The API note and the dated 'checked 23 Oct 2026' remark are tangential to invoking this tool and could be trimmed.

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 and no output schema, the description carries the explanatory load and does so adequately: it says what comes back and that a follow-up browser action is required. What is missing is any mention of account prerequisites or what happens if the user is not signed into Findymail.

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 baseline of 4 applies. The description does not waste words inventing parameter detail.

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 states a specific verb and resource ('Find email in the user's own Findymail account') and clarifies the tool's actual nature: it returns step-by-step instructions rather than performing the lookup itself. That distinction from a real lookup is stated explicitly ('opens nothing by itself'), which an agent needs, though the name alone would suggest it performs the search.

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 route the agent forward ('then do it with the cotlet_browser_* tools in the user's Findymail Cloud Browser'), which is useful sequencing guidance. But it never says when to prefer this over siblings like findymail_start_lead_search, findymail_verify_email, or cotlet_app_guide, so the choice among Findymail tools is left to inference.

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