listGmailThreads

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

No annotations are provided, so the description carries the full burden. The verb 'Retrieves' clearly indicates a read-only operation, which is a positive behavioral disclosure. However, the description lacks details about auth requirements, return format, pagination behavior, or whether it includes full message content or just thread metadata. It adds minimal value beyond the basic operation.

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 a single sentence, direct, and free of unnecessary details. It front-loads the core purpose ('Retrieves a list of email threads/conversations') and the optional filtering note. No wasted words.

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?

The tool has no output schema, so the description should hint at what is returned, but it only says 'list of email threads/conversations.' This leaves ambiguity about whether it returns thread summaries, IDs, or full message data. Sibling readGmailThread implies this is a lightweight listing, but that is not stated. The description is adequate for a simple list tool but lacks key context about the return value.

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 (query, labelIds, maxResults, includeSpamTrash) have adequate explanations. The description only says 'with optional filtering,' which summarizes but does not add meaning beyond the schema. Baseline 3 is appropriate since 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?

The description uses the specific verb 'Retrieves a list' and clearly identifies the resource as 'email threads/conversations from the user's Gmail account.' It distinguishes itself from the sibling tool readGmailThread by emphasizing 'list' (plural), but it does not explicitly contrast with readGmailThread or other Gmail tools, so it doesn't earn a 5.

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 no guidance on when to use this tool versus alternatives. It does not mention readGmailThread for fetching a single thread or listGmailLabels for labels, nor does it state exclusions or prerequisites. The phrase 'with optional filtering' hints at use cases but is not explicit.

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