get_attachment_content

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

The description discloses the optional saveTo parameter that can write to disk, which implies side effects. However, the annotation declares readOnlyHint: true, suggesting no state change. This is a contradiction, as the tool can mutate disk state. Hence score 1 due to annotation contradiction.

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?

Four sentences, front-loaded with purpose, every sentence adds essential information without redundancy.

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?

No output schema, but description hints at return values for saveTo case. It could be more explicit about the metadata structure, but overall sufficient given sibling tools and context.

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%, baseline 3. The description adds value by explaining the default for includeBase64, the need for environment variable for saveTo, and configuring inline size threshold. This goes beyond the schema.

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 metadata for a specific email attachment and optionally return its base64-encoded content inline,' which is a specific verb+resource. It distinguishes itself from siblings like save_attachment and list_attachments by mentioning when to use the alternative.

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?

Explicitly states 'Use when you need to read or process attachment data in-memory' and 'Prefer save_attachment to write the file to disk instead,' providing clear context and alternative.

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