gmail_search_email_ids

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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds behavioral value by specifying the return shape ('message IDs plus a pagination token') and a performance characteristic ('Cheaper than gmail_search_emails'). It does not mention auth or rate limits, but the annotations cover safety adequately.

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 focused sentences: the first states the action and result; the second provides cost trade-off and read-only note. Every word earns its place, and the most important information is front-loaded.

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 straightforward search tool with rich annotations and an output schema, the description fully covers the essential context: what it returns, when to use it over the sibling, and its safety profile. The pagination mechanism is inherited from the schema, and the output schema presumably documents the return structure.

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?

The description itself does not explain parameters, but the schema provides thorough descriptions for query, page_token, and max_results. Since schema coverage is effectively 100%, the baseline of 3 applies; the description's reference to 'pagination token' simply reinforces the page_token parameter without adding new semantics.

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 states 'Search Gmail and return only message IDs plus a pagination token' with a clear verb and resource. It also distinguishes itself from the sibling tool gmail_search_emails by noting it is 'Cheaper than gmail_search_emails when you only need IDs', making the purpose unambiguous.

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?

Explicit guidance is provided: 'Cheaper than gmail_search_emails when you only need IDs to feed into gmail_batch_read_email or gmail_apply_labels.' This names specific alternatives and the exact scenario in which this tool should be chosen over the sibling.

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