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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuine timing behavior (queued waits until the agent is ready; steering lands at the next model call), but says nothing about permissions, side effects on the agent's current turn, or limits.

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 sentences, purpose front-loaded, and the second sentence spends its words on the one non-obvious decision (delivery mode). No filler or restatement of the name.

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 seven parameters, nested objects, media blocks and no output schema, the description covers purpose and delivery semantics but is thin on interaction with the sibling interaction tools and on what "stored input" is retrievable as. The rich schema carries most of the remaining burden, so 3 is the minimum-viable level.

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 86%, so the baseline is 3. The description goes beyond the bare delivery_mode enum by defining what "queued" and "steering" actually mean and which is the default, adding meaning the schema alone does not convey.

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 ("Sends a message to an agent") plus the effect ("returns the stored input"), so the agent knows exactly what the call does. It does not explicitly differentiate itself from adjacent siblings such as agents_interactions_resolve or agents_cancel, so it falls short of a 5.

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 explains the two delivery modes and establishes queued as the default, which is real usage context. However it never states when to prefer this tool over siblings, nor when steering is the right choice versus queued beyond a bare timing distinction.

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