get_message

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description earns credit beyond that by enumerating what the read yields, including per-recipient delivery status and optional original HTML, which is real behavioral context. Permissions and pagination/limits remain unstated, keeping it below a 5.

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 with zero filler; the return contents are enumerated compactly after the verb and scope.

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?

With no output schema, the description usefully carries the return-value burden by listing the fields returned. It is nearly complete for an agent to call it correctly, missing only caveats about session/origin handling and any size or access limits.

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 description coverage is 100%, so all four parameters are already documented, including the format enum and its "text" default. The description only echoes the text-vs-HTML format choice and adds nothing about origin, workspace_id, or message_id. Baseline 3 is appropriate.

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 ("Read") plus resource ("one message") and an explicit scope of what is returned: body, sender, recipients, attachments, delivery status. This cleanly distinguishes it from list_messages and send_message among the siblings.

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?

"Read one message in full" implies the single-message vs list case, but no alternative is named and there are no stated conditions or prerequisites (e.g., when to prefer list_messages first, or auth/session needs). Usage is inferable but not spelled out.

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