delete_label

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

Annotations already indicate destructiveHint=true, but the description adds valuable platform-specific context: the difference between ProtonMail folder deletion and IMAP keyword limitations. This goes beyond the annotation by explaining real-world behavior and constraints, though it doesn't describe error conditions or return values.

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 extremely concise at two sentences, with the primary action front-loaded ('Delete a label') followed by necessary edge-case clarification. Every sentence contributes useful information without redundancy.

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 destructive tool with no output schema, the description adequately covers what the tool does and when to use it, including a key platform caveat. It could mention success/failure behavior or return value, but this is not essential given the clarity of the description and annotations.

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 input schema provides 100% coverage of both parameters (name and account) with clear descriptions. The tool description does not add additional parameter-level detail, so it correctly relies on the schema. Baseline 3 is appropriate.

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's function: 'Delete a label' and distinguishes between ProtonMail (deletes label folder) and standard IMAP keywords (cannot be deleted server-wide). It differentiates from sibling tools, especially remove_label, by explaining when each is appropriate.

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 provided: 'For ProtonMail, deletes the label folder. For standard IMAP keywords, labels cannot be deleted server-wide — use remove_label on individual emails.' This tells the agent exactly when to use this tool and when to use an alternative.

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