search_messages

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

With no annotations provided, the description fully discloses the client-side matching mechanism, server-side createTime filtering, per-space fetching, and the resolution of senders via People API. It omits mention of rate limits or pagination behavior, but the effect of page_size is described in the schema.

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 with two short paragraphs. The first sentence captures the core purpose. Every sentence adds value: scope, mechanism, sibling reference, and auth requirements. No redundant or filler text.

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 moderate complexity (6 parameters, client-side search across spaces) and an output schema exists. The description covers the algorithm, scope distinction, and OAuth scopes. It does not discuss error handling or what happens with no results, but the output schema likely covers return structure. Overall sufficient for effective invocation.

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?

All 6 parameters have schema descriptions (100% coverage), achieving baseline 3. The description adds value by explaining how parameters like query (case-insensitive substring) and time_filter (applied server-side) are used in the overall algorithm, and notes the max_spaces cap when space_id is omitted.

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 the tool searches Chat messages by text and/or time across one or many spaces. It specifies the client-side substring matching approach and explicitly distinguishes from the sibling tool get_messages for unfiltered single-space retrieval.

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 guidance to use get_messages for a single space without filtering. It also lists required OAuth scopes. However, it does not mention when to use alternative search tools like search_gmail_messages, though that is a different domain (Gmail vs Chat).

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