get_top_senders

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

With no annotations, the description carries the full burden of behavioral disclosure. It explains the tool is analytical and returns a ranked list, implying no destructive side effects. It does not explicitly state read-only behavior or resource consumption, but for a simple analysis tool, the description is adequate.

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 well-structured with a clear purpose statement, usage line, parameter details, and return description. It is front-loaded but slightly verbose due to full parameter documentation. It could be more concise while retaining all necessary 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 that an output schema exists (context: 'Has output schema: true'), the description adequately covers what is needed: purpose, parameters, and return type (ranked list with counts). It also provides usage context. It is complete for a relatively simple tool.

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 0% description coverage, but the description compensates fully by documenting all parameters in the Args section (account, mailbox, days_back, top_n, group_by_domain) with defaults and explanations. This adds significant meaning beyond the bare 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 description clearly states the tool's purpose: 'Analyse a mailbox to find the most frequent senders.' It uses specific verbs and resources, distinguishing it from sibling tools like search_by_sender (which finds emails from a sender) and get_newsletters (which identifies newsletters).

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 context on when to use: 'Useful for identifying key contacts, high-volume senders to filter, or newsletter sources to unsubscribe from.' This gives clear use cases, though it doesn't explicitly state when not to use or mention alternatives. The sibling list helps with differentiation.

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