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

Annotations already declare this is a non-destructive, idempotent mutation. The description adds a genuinely useful behavioral trait beyond them: a closed conversation auto-reopens when the contact writes again, which prevents redundant reopen calls. It stops short of disclosing permissions or error behavior.

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?

Two short sentences, front-loaded with the primary action and followed by the one behavioral caveat. No filler, every clause earns its place.

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 three-param mutation with no output schema and covering annotations, the description supplies the state semantics and the auto-reopen nuance an agent needs. Minor omission is that it never states conversation_id is required or what the call returns.

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 carries the burden, and it does map both meaningful params conceptually: the boolean as read/unread and the status enum as closed/open. The required conversation_id is left implicit, which is the only gap.

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 (mark) and resource (conversation) plus the exact state axes affected: read/unread and closed/open. The purpose is unambiguous and clearly distinct from read-oriented siblings like crm_conversation and crm_inbox.

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?

Usage is implied by the description of the two state toggles, but there is no explicit when-to-use/when-not guidance or reference to alternative tools for conversation handling. It does hint that reopening is unnecessary, but does not frame this as routing guidance.

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