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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, but the description adds non-annotation context: the required token scope ('works with mcp:read tokens') and the opt-in extras model via with=. It does not cover pagination or response shape, though an output schema exists to do that.

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?

Two sentences, front-loaded with the core action and lookup keys, then routing guidance and the read-only scope. No filler and every clause carries distinct information.

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 2-parameter read tool with full schema coverage, complete annotations and an output schema, the description supplies everything missing: sibling disambiguation, the escalation path to diagnose_check, and auth requirements. Nothing needed to invoke it correctly is absent.

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 description coverage is 100% and both parameters carry examples and the full with= field list in the schema itself. The description's 'ask for extras with with=lastResult,lastStatusChange' restates the schema's enum-of-fields rather than adding new syntax or semantics, so baseline 3 applies.

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 a single check's metadata') plus the accepted lookup keys (UID or slug), and explicitly contrasts itself with diagnose_check and list_checks. An agent can distinguish it from all 22 siblings 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: use diagnose_check when you need a full triage briefing, use list_checks when searching by name or label. Both the alternative and the condition that selects it are named, leaving nothing to inference.

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