list_agents

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

No annotations are provided, so the description carries the burden. 'Lists' correctly implies a non-destructive read, but it says nothing about the scope of the listing (all agents vs. running agents), whether results are truncated, or what the response looks like. For a zero-parameter read this is acceptable but thin.

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 front-loaded sentence with the verb and scope in the first few words, and zero filler. It is exactly as long as the information content warrants.

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?

There is no output schema, so an agent cannot learn from structured data what an 'agent' record contains or whether listing is cheap. The description covers the 'what' adequately for a no-param tool but leaves the return shape and any behavioral caveats unstated.

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 takes no parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The schema being an empty object matches the description's lack of parameter claims.

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 ('Lists') and resource ('Shelly agents registered on this device'), which lets an agent distinguish it from siblings like list_repos and read_terminal_output. The only weakness is that 'Shelly agents' is undefined domain jargon, but the purpose itself is unambiguous.

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 only implied: the read-only listing nature is obvious, and no sibling competes for the same resource, so there is no alternative to route between. The description never states when an agent should call this (e.g. before run_command against an agent) or any preconditions.

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