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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, covering the safety profile. The description adds the action semantics (accept vs decline vs close) but doesn't clarify what destruction means here, whether closing is reversible, or any authority/participant prerequisites.

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 efficient sentence covering all three actions with no wasted words. Front-loads the primary verb 'respond' and enumerates the operations compactly.

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?

A 4-parameter required-field mutation tool with no output schema. Annotations cover safety and idempotency, but the description omits prerequisites (e.g., must be a participant) and the outcome of each action, leaving moderate gaps.

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 the enum and op_key retry semantics are fully documented in the schema. The description restates the action meanings but adds no syntax or format detail beyond what the schema provides, so 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 (accept/decline/close) and resource (DM request/conversation), matching the enum values. It's clearly distinguishable from send_dm, request_dm, and list_dms, though it doesn't explicitly contrast with the analogous respond_invitation sibling.

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 implies when to use it (responding to an inbound request, closing a conversation you're in) but names no alternatives or exclusions. An agent must infer that respond_invitation is the parallel tool for a different resource.

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