get_thread_messages

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the read-only nature is expected. The description adds the qualifier 'visible', suggesting some filtering of messages, but it does not clarify what visible means or whether responses include message content, ordering, or metadata. With annotations covering the safety profile, the added behavioral context is modest.

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 a single front-loaded sentence with no filler or redundancy. Every word contributes to identifying the operation and its object, and the core action is clear at the start.

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-only tool with one parameter and no output schema, the description covers the basic operation but leaves ambiguous what 'visible' means and what the response contains (text, metadata, ordering). Since no output schema exists, the description would need additional context about the return shape to be fully complete.

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 input schema has 0% description coverage and only declares threadId as a string with no explanation. The phrase 'for a thread' weakly maps the parameter to a thread identifier, but it does not specify the expected format or how to obtain valid IDs. For a single, obvious identifier parameter this is adequate, though not rich.

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 clear verb (Read) and a specific resource (visible messages for a thread), which separates it from the sibling get_thread that would target thread metadata. It could be stronger by explicitly naming the sibling it is not, but the resource identification is sufficiently clear.

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 the tool is used when a thread ID is available and visible messages are needed, but it provides no explicit guidance for when to choose this over get_thread or list_threads. No prerequisites, exclusions, or alternatives are mentioned, leaving the usage context implicit.

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