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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the description doesn't need to restate those. It adds valuable behavioral context: the code is single-use, expires in 15 minutes, and enrollment is deliberately manual. This goes beyond what annotations provide and helps the agent understand the operational implications.

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?

Three sentences, each earning its place: what the tool does, how to handle the output, and a critical behavioral caveat. The most important information (single-use, 15-minute validity) is front-loaded, and the manual-enrollment warning is placed at the end as a clarifying note.

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 zero-parameter tool with an output schema, the description is complete. It explains the tool's role in the mesh enrollment flow, the code's properties, and the manual-enrollment constraint. An agent has everything it needs to decide when to call this tool and what to do with the result.

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?

The tool has zero parameters, so the schema provides no parameter semantics. The description compensates by explaining what the tool produces (a single-use pairing code) and its validity window (15 minutes). Since there are no parameters to document, the description fully covers the semantic space.

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?

The description states a specific verb ('creates'), a specific resource ('single-use pairing code'), and a clear purpose (allowing another machine to join the mesh via agent_mesh_join). It also distinguishes itself from sibling tools like agent_mesh_create and agent_mesh_join by explaining the code's role in the enrollment flow.

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 explicitly tells the agent when to use this tool: to generate a code for another machine to join the mesh. It also provides a clear exclusion: 'having a cloud token does NOT put a machine in the mesh,' which prevents misuse. It names the complementary tool (agent_mesh_join) and instructs the agent to give the code to the user.

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