mark_message_spam

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

Annotations already declare readOnly=false, idempotent=true and destructive=false, so the safety profile is covered. The description adds essentially nothing beyond that: it doesn't say whether the move is reversible, what happens if the message is already in Spam, or that it returns no/limited data.

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 short sentence with the action and destination front-loaded; nothing is wasted, though it is arguably under-specified rather than genuinely concise.

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 one-parameter mutation tool with no output schema, the description should at minimum pin down the messageId format and note the reversibility/idempotency behavior. It does neither, so an agent must probe or guess before calling.

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 0% for the single messageId parameter, so the schema gives no format information. The description says only 'a message' and never clarifies whether messageId is an internal ID, an RFC 822 Message-ID, or a thread-scoped identifier, leaving the caller to guess.

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 ('Moves') and resource ('a message') with the destination ('the Spam folder'), which distinguishes it from unmark_message_spam and trash_message. It does not explicitly contrast with the sibling mark_thread_spam, so the message-vs-thread distinction must be inferred from the name.

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 intent (message is spam → move it to Spam) is implied clearly enough by the description, but there is no explicit guidance on when to prefer this over mark_thread_spam or when to use unmark_message_spam to reverse it.

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