gmail_semantic_search

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

Annotations already declare read-only, idempotent, and non-destructive behavior, so 'Read-only' in the description earns no credit. It does add genuine context beyond annotations: the first-run index build causes latency, embeddings are computed locally (a privacy/data-residency signal), and multilingual coverage including Spanish is disclosed.

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?

Three short sentences, zero waste, with the core purpose front-loaded and the operational caveat immediately after. Every sentence carries distinct information.

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 two-parameter search with rich annotations and no output schema, this covers purpose, cost, and language scope adequately. Remaining gaps are how index staleness is handled and that gmail_reindex_semantic exists to rebuild it, plus no hint about result ordering.

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 coverage is 100%, so both parameters are already documented with natural-language guidance and bounds. The description adds nothing beyond the schema about query format, ranking behavior, or how max_results interacts with relevance ordering, so the baseline 3 applies.

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 ('Searches inbox threads') plus the distinguishing mechanism ('by meaning using local embeddings'), which implicitly separates it from the keyword-based gmail_search_messages sibling. It stops short of naming that sibling explicitly, so the differentiation is inferential rather than stated.

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 implies when the tool is appropriate ('by meaning') and warns that the first run builds the index and is slow, which is useful operational context. However, it never says when to prefer it over gmail_search_messages or when to call the sibling gmail_reindex_semantic, so usage is only implied.

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