mail_pin_email

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

The description discloses the behavioral effect (setting $flagged keyword, visual flag icon) and explains the boolean pin parameter. However, it does not mention idempotency, error handling, or permission requirements. Without annotations, this is adequate but leaves gaps.

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: two lines defining the action and effect, followed by a clear args list. No wasted words; key information is front-loaded.

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 simplicity (2 parameters, no annotations, output schema exists), the description covers the core functionality and parameter details well. It could mention the return value or error cases, but the presence of an output schema partially mitigates this gap.

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?

With 0% schema description coverage, the description fully explains the two parameters: email_ids as a list of JMAP IDs, and pin as a boolean with default True. This adds necessary meaning beyond the raw JSON schema.

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 tool name and description clearly state that it pins or unpins emails by setting the $flagged keyword. It distinguishes itself from sibling tools like mail_mark_email_read or mail_manage_email_labels by focusing specifically on the flag/star functionality.

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 provides basic instruction on how to use the tool but lacks guidance on when to use it versus alternatives (e.g., mail_manage_email_labels). There is no explicit when-to-use or when-not-to-use context.

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