Message Get

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so safety is covered. The description adds real value beyond that by disclosing the returned payload: sender, recipients, subject, plain text, detected language, translation, attachments, and draft/internal-note flags. With no output schema, this return-shape disclosure is the key behavioral contribution.

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?

A single front-loaded sentence; the enumerated return fields each earn their place since no output schema exists to carry that information.

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 the absence of an output schema, describing the response contents makes this definition nearly self-sufficient for correct invocation. The remaining gap is usage guidance about when to prefer this over conversation_messages/conversation_thread.

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?

Both parameters are fully documented in the schema (100% coverage), including how to find the organizationId and messageId. The description adds no syntax, format, or scoping detail beyond the schema, so the baseline 3 applies.

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 and resource ('Get one message by id') and enumerates the fields returned, which makes the read-only fetch role unmistakable against siblings like message_update, message_send, and message_delete. It does not explicitly name or contrast with a sibling tool, so it stops short of the top tier.

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 when-to-use guidance, no prerequisites, and no mention of alternatives such as conversation_messages or conversation_thread for retrieving messages. The only routing hint (how to find a message id) lives in the schema, not the description.

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