read_emails

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

With no annotations provided, the description carries the full burden of disclosing side effects. 'Read emails' implies a non-mutating operation, and the description adds the aggregation behavior. However, it does not explicitly state that emails are not marked as read, mention required permissions, or describe the return format, leaving some behavioral gaps.

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 that effectively communicates the core purpose and the key account behavior. It is front-loaded with the verb and resource, and every word earns its place with no unnecessary filler.

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 description gives the essential purpose and account aggregation behavior, which is adequate for a simple read tool. However, it lacks sibling differentiation (especially from 'search_emails'), does not mention the query parameter or return structure, and has no annotations or output schema to fall back on, leaving some contextual gaps.

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 schema already provides descriptions for all 4 parameters (100% coverage), so the baseline is 3. The description's mention of omitting the account overlaps with the schema's description of the account parameter, adding no new semantic value. It does not compensate for any gaps beyond what the schema already covers.

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 'Read' with the resource 'emails' and clearly states the scope: one account or aggregated across all enabled accounts. It is clear in its purpose, but it does not explicitly differentiate from the sibling tool 'search_emails', which might overlap in function.

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 like 'search_emails' or 'get_email_thread'. It only explains the account omission behavior, not the appropriate context for choosing this tool over others.

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