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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds genuinely new context: each row returns one of connected/not_connected/not_available plus the reason an integration is disabled on this account, and that reads are free. That is real behavioral value beyond the structured fields.

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-loaded with the resource list and the state semantics; every sentence carries information. Slightly padded with framing like 'the measurement behind SEO and outcomes' and 'honest state', which is flavor rather than instruction.

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 parameters and no output schema, the description compensates by spelling out the possible per-row states and that a reason accompanies not_available, which is exactly what an agent needs to interpret the response. Missing only the row field names for machine parsing.

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 no parameters, so the schema carries nothing to document and the description needs only to confirm a no-argument call, which it implicitly does. Baseline 4 for zero parameters applies.

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+resource (listing connections) and enumerates exactly which sources are covered — GA4, Search Console, Google Business Profile, LinkedIn/Reddit — so an agent can distinguish it from start_connection, poll_connection and disconnect_connection at a glance.

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?

The phrase 'Read-only, free' implies this is the safe discovery call, but there is no explicit when-to-use or routing versus poll_connection/start_connection/disconnect_connection. Usage is implied rather than stated.

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