Search emails

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description adds real value by naming the exact return fields (uid, date, from, to, subject, read flag) and the sort order (newest first). It omits pagination or truncation behavior beyond the schema's limit, which keeps it just shy of a 5.

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?

Four short sentences, nothing repeated, and the default-behavior note is front-loaded right after the purpose. Every clause carries information the agent needs.

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 ten-parameter read tool with full schema coverage and a stated return shape, the description covers what an agent needs to call it correctly. Only minor gaps remain, such as how the limit interacts with truncation and whether folder paths are case-sensitive.

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 every one of the ten parameters is already documented with format hints such as YYYY-MM-DD and the INBOX default. The description adds only the aggregate notion of 'no filters', which is a baseline-3 contribution.

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 (search a folder) and names the returned fields, which makes it clearly distinct from read_email and list_folders. It stops short of explicitly contrasting itself with the siblings that also touch messages, but the intent is unambiguous.

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 sentence 'With no filters returns the latest messages' tells the agent what happens with an empty query, which implies the browsing use case. There is no explicit statement of when to prefer read_email or mark_as_read, and no exclusions or prerequisites.

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