unsubscribe

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

Beyond the annotations (readOnlyHint=false, openWorldHint=true, idempotentHint=true, destructiveHint=false), the description discloses crucial side effects: makes an outbound HTTPS request, confirms the address is live, cannot be undone, and never modifies the mailbox. It also details the duplicateOf behavior and force:true for retries. No contradictions 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?

The description is dense but well-organized with 'USE WHEN', 'DO NOT USE', and 'SIDE EFFECTS' sections. Every sentence adds value: security protocol, lacking URL parameter, redirect limits, non-error on failure. Despite length, it remains front-loaded and efficiently structured.

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?

Given the tool's complexity (external network call, alternative handling, duplicate prevention), the description covers all aspects: side effects, alternatives, failure modes, and output semantics (duplicateOf, options). An output schema exists, so return values are covered. No significant gaps remain.

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 coverage is 0%, so the description must explain parameters. It implicitly defines threadId as the thread containing the mailing list email. It explicitly explains force:true for a deliberate second attempt. While it doesn't specify threadId's exact format, it adds meaningful context beyond the bare schema. Slight room for more explicit parameter documentation.

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 action: 'Unsubscribe from the mailing list a thread came from, via the sender's RFC 8058 one-click endpoint.' It clearly distinguishes from sibling tools (e.g., list_unsubscribe) by emphasizing it actually performs the subscription removal. The scope and method are precise.

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?

Explicit guidance is given: 'USE WHEN: the user wants off a newsletter' and 'DO NOT USE: to check whether unsubscribing is possible (use list_unsubscribe — it contacts nobody).' It also suggests pairing with archive/trash or create_filter for post-processing. This fully covers when and when not to use, with alternative tools named.

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