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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds a non-obvious behavioral trait: the browser extension cannot be driven by an agent, which is crucial for an agent to understand. It also clarifies that the check involves multiple state components. No contradiction with 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?

Three sentences, each earning its place. The first states the core purpose and enumerates outputs. The second provides usage guidance. The third adds a crucial limitation. It's front-loaded with the purpose and has zero filler.

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 status tool with no output schema, this description is fully complete. It explains what the tool checks, when to use it, and the agent-specific limitation. Nothing an agent needs to correctly invoke it is missing. The conceptual return values are described adequately.

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 0 parameters and schema coverage is 100% (empty). Per the calibration, 0 params baseline is 4. The description adds no parameter-specific details because there are none, but it does describe what the tool reports (connected/disconnected, synced, can_pull + how), which is effectively the return semantics expected.

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 ('Check') and resource ('whether the user's tweets can be pulled'), then enumerates the exact components: X API connection state, extension sync recency, and the rolled-up can_pull with source. This clearly distinguishes it from other status/get tools like get_sync_status or get_bookmark_sync_status by focusing on the connection for pulling tweets.

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 explicit usage context: 'Use this before a sync, or when the user asks why bookmarks aren't updating.' This tells an agent exactly when to invoke it. It doesn't name explicit alternatives or when-not-to-use cases, but the provided scenarios are strong practical guidance. The note about the extension being browser-only adds an important limitation.

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