get_thread

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

The annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavior beyond annotations: messages are returned oldest first, folders include inbox/sent/user folders, drafts are omitted, and threads are reconstructed from Message-ID/References headers. It does not cover permissions, pagination, or response shape, but with annotations present this is a strong disclosure.

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 four compact sentences, front-loads the core action and scope, then adds ordering, draft exclusion, reconstruction behavior, and format advice. Every sentence earns its place with no repetition or 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?

For a read-only tool with fully documented parameters and annotations covering safety, the description gives enough behavioral context to call it correctly: thread scope, ordering, folder coverage, draft omission, and format recommendation. It does not mention pagination or response size limits, and with no output schema those details remain slightly underspecified.

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 100%, and the schema already documents both threadId and the full messageFormat enum, explicitly labeling PLAIN_TEXT as recommended. The description's 'Use PLAIN_TEXT to save context' largely repeats the schema's recommendation rather than adding new parameter meaning, so the baseline 3 is appropriate.

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 a specific verb and resource: retrieves an email thread with all its messages, oldest first, across folders. The thread-level scope and 'all its messages' distinguish it from single-message tools like get_message and from search-oriented siblings like search_threads without requiring the schema to be opened.

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 no explicit when-to-use or when-not-to-use guidance and does not route the agent to alternatives such as get_message or search_threads. The only directive, 'Use PLAIN_TEXT to save context,' addresses messageFormat selection rather than whether to call get_thread at all.

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