indico_list_instances

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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile and the fact that reachable instances are external/undisclosed. The description adds the useful workflow context that the returned names are the input to other tools, but says nothing about ordering, filtering, or failure behavior when no instance is reachable. Adequate given annotations carry the safety burden.

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 16-word sentence, front-loaded with the action and resource, with the workflow hint appended rather than padding. Nothing is wasted.

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?

An output schema exists, so return values need not be described, and with zero parameters there is little else to specify. The definition is essentially complete, missing only minor operational context such as behavior on unreachable instances.

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 zero parameters, so the baseline is 4. The description does explain the semantics of the `instance` parameter on other tools, which is a small bonus, though it cannot add meaning to this tool's own (empty) argument set.

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+resource ('List the Indico instances this server can reach') and is unmistakably the discovery/enumeration tool among siblings that all operate on events, sessions, contributions and registrations. No other sibling returns instance names, so the agent can route here without checking other schemas.

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 second clause is actionable guidance: pass a returned name as the `instance` argument to the other tools, which tells the agent this is the prerequisite discovery step. It does not, however, state any exclusions or name an alternative, so it stays at 4 rather than 5.

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