mail_recent

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

No annotations are provided, so the description carries the full burden. It does not state that this is a safe read-only operation, the sort order beyond 'most recent', whether results are capped only by the limit, or anything about pagination. It is adequate for a simple list tool but adds no behavioral context beyond the purpose.

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, zero waste, with the core purpose front-loaded before the routing triggers. Every clause earns its place.

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 read-only, zero-required-param list tool with full schema coverage and no output schema, the description covers what an agent needs to select and invoke it. It only omits minor operational detail such as ordering guarantees, which is a small 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?

Schema description coverage is 100%, with each of the four parameters (limit, days_back, unread_only, include_junk) documented including defaults and the Mail.app read-status nuance. The description adds nothing beyond the schema, so the baseline 3 is appropriate.

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?

States a specific verb and resource ('Get most recent emails') and immediately draws the boundary against semantic-search siblings such as mail_search and smart_search. An agent can distinguish it from mail_search without opening either schema.

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?

Explicitly enumerates the user utterances that should route here ('recent emails', 'latest emails', 'what emails did I get', 'unread emails') and names the alternative modality (semantic search) it is not. This is exactly the when-to-use signal an agent needs.

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