list_emails_month

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: it's a read operation (implied by 'List'), returns sorted data ('newest-first'), specifies the output format ('array of {id, subject, from, date} objects'), and mentions the id's purpose ('globally unique identifier — use it with fetch_email_content'). It lacks details on pagination, rate limits, or error handling, but covers essential operational context.

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 highly concise and well-structured in two sentences: the first states the purpose and output format, and the second explains the id's utility. Every sentence adds value without redundancy, making it easy to parse and front-loaded with critical information.

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 moderate complexity (1 parameter, no output schema, no annotations), the description is largely complete. It covers the action, time scope, output structure, sorting, and id usage. However, it doesn't address potential edge cases like empty results or authentication needs, leaving minor gaps in contextual coverage.

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 has 100% description coverage, with the 'mailbox' parameter fully documented in the schema itself. The description adds no additional parameter information beyond what the schema provides, such as examples or constraints. This meets the baseline of 3 since the schema handles the parameter documentation adequately.

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 specific action ('List all emails received in the last 30 days'), resource ('emails'), and scope ('last 30 days'). It explicitly distinguishes from sibling tools like list_emails_24h, list_emails_7days, etc., by specifying the time window, making the purpose unambiguous and well-differentiated.

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 clear context for when to use this tool (for emails in the last 30 days) and implies an alternative (fetch_email_content for full email reading). However, it doesn't explicitly state when NOT to use it or compare it to other time-based siblings like list_emails_quarter or list_emails_year, which could help avoid misuse.

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