read_attachment

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

With no annotations provided, the description carries the behavioral burden. It states that the tool extracts text and supports specific formats, which is useful. However, it does not mention truncation via max_chars or behavior for unsupported attachment types, leaving some important 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 concise and front-loaded with the core action, followed by ref semantics and supported formats. Every sentence adds useful information with no 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?

This is a simple tool with an output schema, and the description covers the core purpose, ref semantics, and supported formats. It is adequate, but missing clarification about mail_id provenance and max_chars behavior leaves room for agent misinterpretation.

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 description coverage is 0%, so the description must compensate. It usefully explains `ref` as a filename or index from read_mail. However, `mail_id` and `max_chars` are not described at all; their meanings are only inferable from the parameter names and default value.

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 a specific verb and resource: 'Trích text từ một tệp đính kèm' (extract text from an attachment). This clearly differentiates it from sibling tools like read_mail, get_thread, list_folders, and search_mail, none of which target attachments.

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 gives clear workflow context by stating that `ref` is a filename or index from read_mail, which tells the agent how the tool relates to a sibling. It does not explicitly list when not to use it, but the attachment-specific purpose makes the appropriate use case clear.

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