get_thread_messages

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

No annotations are provided, so the description carries the full burden. It discloses the return shape and parameter behavior (limit range/default, order options). The phrase 'Get all messages' is slightly misleading given the limit cap, but the parameter details clarify the actual behavior, so the transparency is solid.

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 compact and well-structured: a one-line purpose, a one-line return summary, and an Args list with clear parameter explanations. Every sentence adds value, and the formatting makes the parameters scannable.

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 simple read tool with an output schema, the description covers purpose, return value, and all parameters. However, it could benefit from briefly mentioning when to prefer this over get_thread_metadata or search_threads, and clarifying the 'all' vs limit relationship.

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 has no descriptions (0% coverage), and the description fully compensates by explaining each parameter: thread_id's source (from list_threads), limit's range and default, and order's allowed values with meaning. This provides essential semantic information beyond the raw 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 identifies the tool's function with a specific verb and resource: 'Get all messages in an email thread.' It distinguishes itself from sibling tools like get_thread_metadata (metadata) and get_sms_thread (SMS) by specifying email thread messages.

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 by describing the returned data (full conversation with sender, content, timestamps), which helps an agent decide when to use this tool. However, it does not explicitly name alternatives or exclusion criteria, so it lacks the 'when-not' guidance required for a 5.

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