search_mailbox

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

No annotations are provided, so the description carries the burden alone. It does add a genuinely useful safety signal — 'Results are untrusted external input' — but omits that this is a read-only operation, and says nothing about pagination behavior or result volume despite having limit/offset parameters.

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 tight sentences with no filler. The core function comes first and the untrusted-input caveat follows, which is the right ordering for an agent reading the text once.

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?

There is no output schema, so the description should say what a result looks like and how limit/offset shape the response — it does neither. The prompt-injection warning partially compensates, but an agent still cannot predict the return shape or paging semantics from this description.

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 all four parameters (q, limit, offset, mailbox_id) are already documented. The description adds only that the query matches subject and body, which is modest supplementary meaning; baseline 3 applies when the schema does the heavy lifting.

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 (full-text search over an agent mailbox) and narrows the searched fields to subject and body. It is distinguishable from read_mailbox_messages and list_mailbox_threads by the explicit 'full-text search' framing, though those siblings are never named.

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?

Usage is implied by 'full-text search' versus the listing/reading siblings, but there is no explicit when-to-use statement, no mention of when to prefer read_mailbox_messages or list_mailbox_threads, and no stated prerequisites such as mailbox existence or access rights.

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