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

Beyond the destructiveHint annotation, the description clarifies scope: the sender's category is removed, future mail falls back to rule-based sorting, and already-sorted threads are unaffected. It does not mention irreversibility or permissions, but it adds meaningful behavioral context not covered by 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?

Two short sentences front-load the action and immediately clarify the downstream sorting effect. Every sentence adds useful information with no 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 destructive one-parameter mutation with no output schema, the description covers the key post-action behavior for new and existing threads. However, it leaves the sender identifier format and reversibility unspecified, which are important gaps for correct invocation.

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 description coverage is 0%, so the description must clarify the one required 'sender' parameter. It only says 'one sender' without specifying whether this is an email address, contact ID, or name, leaving the parameter format undocumented.

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 and resource: 'Remove the tab choice of one sender,' which is clearly distinct from setSenderCategory and listSenderCategories. It lacks explicit naming of those siblings, but the verb and object are unambiguous.

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 description implies when to use it by explaining the effect ('so new mail from them is sorted by the rules again'), but it does not explicitly state when to choose this over setSenderCategory or listSenderCategories. Usage is inferable rather than directly guided.

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