therapyportal_get_thread_messages

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

Goes beyond the readOnlyHint annotation by disclosing two behaviors annotations can't express: it does not mark the conversation read, and the returned content is third-party authored and must be treated as untrusted data rather than instructions. That injection-resistance warning is exactly the security context an agent needs for a message-reading tool.

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: operation first, then side-effect clarification, then the trust/safety caveat. Every sentence carries distinct, non-redundant information with nothing repeated from the schema.

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 single-parameter read tool with no output schema, the description covers what is returned (message text), its trust status, and the absence of a read-marking side effect. Nothing needed to invoke or interpret the result safely is missing.

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 100% and there is a single parameter, so the schema already carries the type constraints. The description still adds value by specifying provenance — the thread id must originate from therapyportal_list_message_threads — which tells the agent how to obtain a valid 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?

Specific verb+resource: read the messages in one named secure-message conversation. It also identifies the source of the identifier (therapyportal_list_message_threads) and the domain (TherapyPortal), which distinguishes it from siblings like therapyportal_list_message_threads and therapyportal_download_document.

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?

Explicitly states the prerequisite chain — the thread_id must come from therapyportal_list_message_threads — and clarifies the read-only-ness ('does not mark the conversation read'), which steers agents away from expecting a read-receipt side effect. No explicit exclusions or when-not guidance, but the selection context is clear.

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