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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description still adds real behavioral context beyond that: billing output is role-gated, repository cards and jobs are previews rather than full data, and daily usage is only authoritative when snapshot.usageCompleteness is complete. It does not mention failure modes or auth requirements, keeping it just shy of a 5.

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?

Four short sentences, front-loaded with the primary purpose before the caveats and alternative. Each clause carries concrete information (role gating, preview semantics, completeness flag, routing), with only mild density cost from the dotted field name 'snapshot.usageCompleteness'.

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 single-parameter read tool with full annotations and an output schema, the definition covers what the agent needs: purpose, contents, role-based partial results, data-completeness semantics, and the preferred alternative for spending. The remaining gap is minor — nothing about failure behavior if the workspace is inaccessible or the role lacks billing access beyond the parenthetical.

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?

Only one parameter exists and schema description coverage is 100%, with the schema itself noting the ID comes from list_workspaces. The description adds no format, scope, or constraint detail about workspaceId, so the baseline of 3 applies when the schema does all the work.

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 ('get an overview of a Runzumi workspace') and immediately enumerates what the overview contains: runner status, recent CI jobs, billing. It also carves out the boundaries against siblings by noting that repository cards and recent jobs are previews and that spending should go to get_usage instead, so an agent can distinguish it from open_dashboard and get_usage without opening a schema.

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?

Gives explicit routing guidance: use this for the workspace overview, and 'For workspace spending, prefer one get_usage call.' It also implies a permission condition ('if the user role permits it'). It stops short of a full when-not list (e.g. when to prefer open_dashboard or list_runs for job detail), so it is strong but not exhaustive.

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