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

Annotations already declare read-only, idempotent, non-destructive, so the description is not burdened with the safety profile. It still adds real context beyond structured fields: the pagination round-trip ("pass pagination.cursor back as cursor") and the auth scope ("works with mcp:read tokens"). The "Returns {data, pagination}" sentence is mildly redundant given an output schema exists.

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 tight sentences ordered by importance: what it is, filter scope, pagination mechanics, then sibling routing. No filler and nothing repeated from annotations.

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 read-only list tool with full schema coverage, an output schema, and rich annotations, nothing an agent needs is missing: purpose, filtering, pagination loop, auth scope, and alternatives 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 description coverage is 100%, so the schema already documents all six parameters in detail. The description's "filtered by name/slug substring, labels, or check group" merely paraphrases q, labels, and checkGroupUid and says nothing about `with` or `limit`, so the 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?

Starts with a specific verb+resource ("List monitoring checks") and immediately scopes it to the organization with named filter dimensions. It explicitly distinguishes itself from two siblings by name (diagnose_check, get_check), so an agent can route 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?

States the positive case ("browsing or filtering a fleet of checks") and two negative cases with named alternatives: diagnose_check for single-check health, get_check when the UID/slug is already known. The selection rule is fully determined.

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