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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds behavioral context: that live connections allow scripts to reach signed-in pages without sign-in steps, and that needing reauth explains pauses. However, it doesn't detail the exact return format, which could be a gap, but the extra context is valuable beyond 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?

The description is two paragraphs, each with a clear purpose: first defines the output, second explains usage and exclusions. It is front-loaded with the core function. Slightly verbose with the URL and extra clarifications, but each sentence adds value, so no waste.

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 zero-parameter, read-only list tool, the description covers what is returned, the meaning of statuses, and how to interpret results for scripts. It also clarifies limitations (adding logins is user-side). Without an output schema, it explains return fields adequately. Small gap: doesn't mention any pagination or limits, but for a likely small list this is acceptable.

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 has zero parameters, so there are no parameter semantics to add. The description focuses on the output and usage, which is appropriate. Since there are no params, the baseline is 4, and the description meaningfully explains the return fields.

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 clearly states the tool lists saved logins and enumerates the information included (id, site, account, status, last use), with a specific verb and resource. It distinguishes itself from siblings by explicitly mentioning it lists existing connections, not creating or deleting them.

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?

Provides explicit guidance on when to use (before a task needing an account) and what the statuses mean ('needs_reauth' or 'expired' causes pauses). It also clarifies that adding a new login is the user's responsibility and points to the dashboard, preventing confusion with delete_connection.

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