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

Annotations already cover readOnly/idempotent/non-destructive, but the description adds real behavioral context beyond them: copying the command installs nothing and authorizes no private tools, the card should be called only once, and text-only hosts behave identically. This clarifies absence of side effects and host compatibility.

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?

Four tightly packed sentences, front-loaded with the purpose before the prerequisite flow and the caveats. Nothing is padded, though the density makes it slightly harder to scan than a crisper two-sentence form.

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 one-parameter display-only tool with full annotation coverage and no output schema, the definition supplies the workflow, the side-effect disclaimer, and host behavior. It is essentially complete, with only sibling differentiation left unaddressed.

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?

Schema description coverage is 100% and the enum values are documented, so the schema already does the heavy lifting. The description's 'with the returned mode' merely echoes the schema's own note that the value comes from find_mcp_tools, adding little new meaning.

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+resource: 'Show sign-in availability or the one-step install card.' That is clear and scoped, and it names find_mcp_tools as the routing prerequisite. It does not differentiate itself from the other sibling show_tool_preferences_card, so it lands just below the top band.

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 gives an explicit sequence: first call find_mcp_tools with operation ask, and only if that returns kind account/connect, call this card once with the returned mode. The condition that selects this tool and the alternative path (don't call it otherwise) are both spelled out.

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