read_thread

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

Annotations already declare readOnly=true, idempotent=true, non-destructive, closed-world. The description adds valuable behavioral detail beyond that: tool output and attachments are omitted, and message text is capped at 8000 characters. These are non-obvious constraints that affect how an agent interprets results.

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?

Three short sentences, front-loaded with the purpose, then constraints, then pagination instruction. No wasted words.

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?

Given three parameters, one required, no output schema, and no annotations about return shape, the description covers the essential behavioral constraints and pagination pattern. It could mention what 'state' includes or whether turnLimit controls the page size, but it is largely complete for the tool's complexity.

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 0%, so the description must compensate; it does so by explaining the purpose of beforeCursor for pagination. However, it doesn't describe threadId or the turnLimit parameter (1-100), leaving those semantics implicit. Baseline with no schema descriptions would be low, so the partial compensation earns a 4.

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?

States a specific verb (read) and resource (a peer thread's state plus a page of conversation messages), scoped to 'this project'. It is clearly distinguishable from siblings like create_thread, list_threads, and send_message_to_thread.

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 explains pagination usage ('Use the returned page.beforeCursor for older turns'), which gives a clear operational context. It doesn't describe when to prefer this over alternative reading tools, but the sibling set doesn't include an obvious competing read tool.

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