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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds real context beyond that: it explicitly says the tool 'opens nothing by itself' and that execution must happen in the cloud browser, which prevents an agent from assuming a side effect. It does not describe the shape of the returned steps.

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?

Two sentences, but the second half is padding about Vtiger's REST API rate limits and a 'checked 22 Oct 2026' note about MCP servers — trivia that does not help an agent invoke this zero-parameter tool. The critical disclosure ('opens nothing by itself') is buried after the misleading first clause rather than front-loaded.

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 output schema, the description carries the burden of explaining the return value, and it only says 'step by step (screens, buttons, fields)' without indicating structure or how the agent should consume it. For a simple read-only, zero-parameter tool this is close to adequate, but the ambiguity between 'lists contacts' and 'returns instructions' leaves a real gap for an agent deciding what it will receive.

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 there is no parameter semantics to explain and the baseline is 4. The description appropriately spends no words on arguments.

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 opens with 'List contacts in the user's own Vtiger account', but the very next sentence reveals the tool does not list anything: it 'Returns how to do it in Vtiger step by step (screens, buttons, fields) and opens nothing by itself'. The actual function (returning an instructions guide) is stated, but only after a sentence that implies data retrieval, so an agent skimming the first clause would mis-select it.

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 onward: 'then do it with the cotlet_browser_* tools in the user's Vtiger Cloud Browser', which is a genuine alternative-path instruction. However, it gives no guidance on when to prefer this guide over siblings like vtiger_list_deals or cotlet_app_guide, and no preconditions for calling it.

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