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

Annotations already cover read-only, idempotency and safety, but the description adds behavior the annotations cannot convey: the server does not count all computers, so possibly_truncated is always true and the result never proves completeness. That is a genuinely important caveat for an agent deciding how to page or whether to trust the list.

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?

Front-loaded with scope and the truncation caveat, which are the highest-value facts. Slightly over-long: enumerating returned fields (provider, computers, applied limit, possibly_truncated) duplicates the output schema that already exists.

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?

Given a single optional parameter, an output schema, and full annotation coverage, the description leaves nothing an agent needs unanswered: scope, exclusions, paging caveat, and how results feed downstream tools are all present.

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%, so limit is already documented structurally. The description adds the intent behind it — bounding how many candidates the agent inspects at once — which layers in query/paging semantics beyond the field definition.

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 with scope: 'List non-deleted Celesto Cloud computers in the authenticated organization.' It further narrows scope by excluding GitHub CI runner machines, which is critical disambiguation among compute-listing tools.

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?

Explicitly tells the agent what to do with results ('pass a returned computer_id to the other computer tools') and names the alternative for a specific need ('Use cloud_computer_info for names and resource details'). Routing between siblings is unambiguous.

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