gmail_batch_read_email

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

Annotations already declare readOnlyHint=true and idempotentHint=true, but the description adds valuable context beyond that: 'Bodies are passed through the masking layer before return' and 'HTML is stripped to text when that's all that's available'. These are important behavioral traits not visible in annotations.

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 three sentences, front-loaded with the primary action, and every sentence adds meaningful information. The final 'Read-only' is redundant with annotations but does not detract from conciseness.

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?

Given that an output schema exists, the description does not need to detail return values. It covers the key behaviors: batch size, body decoding, HTML stripping, and masking. However, the lack of mention of the 'format' parameter is a minor completeness gap.

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 description coverage is 0%, so the description must compensate. It mentions 'message IDs' and the 100 limit, but it completely omits the 'format' parameter that allows 'metadata' instead of 'full'. This is a significant gap since the agent cannot know about this option from the description alone.

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 'Fetch full content for up to 100 Gmail messages by ID', which is a specific verb ('fetch'), resource ('Gmail messages'), and scope ('by ID', 'up to 100'). This distinguishes it from sibling tools like search functions and thread reads.

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 usage when message IDs are already known ('by ID'), but it does not explicitly state when to use this over alternatives or provide exclusions, such as 'use search to find IDs first'. No alternatives or when-not-to-use guidance is given.

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