list_emails

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

With no annotations the description carries the full burden, and it does add one genuinely useful fact the schema does not: results are restricted to mail sent from this account, not received mail. However it omits ordering ('recent' is undefined), pagination semantics despite exposing a cursor, and any statement that this is a non-destructive read.

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?

A single front-loaded sentence with no filler; the scope constraint appears immediately. It is efficient, though arguably terse to the point of omitting needed context rather than being optimally sized.

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 simple two-parameter read tool with no output schema, the definition is minimally viable but leaves ordering, result fields and pagination behaviour unaddressed. An agent can invoke it, but cannot predict what it will get back.

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%, so both limit and cursor are already documented in the schema with sensible meanings. The description adds nothing further about them, which is the expected baseline when the schema does the work.

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 ('List recent emails') plus a scope qualifier ('sent from this account'), which lets an agent separate it from get_email and send_email. The qualifier 'recent' is left undefined, so it is clear but not fully differentiated in behaviour.

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?

There is no statement of when to use this tool versus get_email or any other sibling, and no prerequisites or exclusions are mentioned. Usage is only inferable from the name, which is the definition of no real guidance.

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