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. It explains the return value ('Ranked list of senders...') but does not explicitly state that the tool is read-only or has no side effects. However, the analytical nature is implied, and no destructive behavior is indicated.

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 concise, using only necessary sentences. It front-loads the purpose, then lists parameters and return value in a clear 'Args' and 'Returns' structure. No superfluous text.

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 has 5 parameters, no annotations, and an output schema, the description covers the essentials: what the tool does, each parameter with defaults, and the return format. It is complete enough for an agent to use correctly.

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 compensate. It lists all parameters with brief explanations, including sensible defaults and the note that 'days_back=0 = all time'. This adds meaning beyond the bare schema definitions.

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.' This verb+resource combination is specific and distinguishes it from sibling tools like 'list_inbox_emails' or 'search_emails' by focusing on aggregation and ranking of senders.

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 concrete use cases: 'identifying key contacts, high-volume senders to filter, or newsletter sources to unsubscribe from.' While it doesn't explicitly state when not to use or name alternative tools, the context is helpful for an AI agent.

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