search_threads

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes the return format ('matching thread summaries with subject, snippet, and message count') and the constraint about requiring at least one filter. It implies a read-only operation by using 'Search' and 'Returns', but does not explicitly state it is non-destructive or mention any rate limits or authentication requirements. Overall, it provides solid context but leaves a few behavioral aspects implicit.

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 and well-structured. It opens with a one-sentence purpose, then one sentence about return value, one sentence about the required filter condition, and a neatly formatted Args list. Every sentence earns its place, and the structure makes it easy to scan for key details like the filter requirement and parameter semantics.

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?

Despite having no annotations, the description is complete enough for an agent to select and invoke the tool correctly. It covers the main behavior, return format, filter prerequisites, and parameter ranges. An output schema exists, so detailed return types are not strictly necessary, but the description still provides a helpful summary. Minor gaps like pagination (beyond limit) and error behavior are not critical for a search tool.

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, and it does thoroughly. The 'Args' section explains each parameter's purpose in plain language: query 'searches subject and message content', inbox_id 'Filter by inbox (recommended)', domain_id 'Filter by domain', and limit 'Max results, 1-100 (default: 20)'. It also clarifies the domain_id/inbox_id relationship in the main description. This adds substantial meaning beyond the raw schema.

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 what the tool does: 'Search across email threads by subject or content.' It uses a specific verb ('search') and resource ('email threads'), and it distinguishes itself from sibling tools like 'list_threads' (which likely lists all threads), 'search_sms' (different resource), and 'get_thread_messages' (retrieves messages). The mention of returning matching thread summaries further clarifies the scope.

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 explicit usage guidance: 'Provide at least one of inbox_id or domain_id.' It also labels 'inbox_id' as 'recommended' for filtering, giving a preference. However, it does not explicitly state when to use this tool over alternatives (e.g., 'use list_threads to list all threads'), so it misses the 'when-not-to-use' aspect. Still, the advice is actionable and clear.

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