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

Annotations already declare this is a mutation (readOnlyHint=false) that is idempotent and non-destructive. The description adds the genuinely non-obvious trait that saving a cadence has no immediate side effect ('never starts a check'), which is the key behavioral fact an agent needs. It omits permission requirements and return behavior, but the safety profile is otherwise covered.

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?

Three tight sentences: purpose and enum values first, the non-obvious side-effect caveat second, then parameter routing and related tools. Every sentence earns its place with no redundancy.

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 mutation tool with full annotation coverage, 100% schema coverage, and an output schema (so return values need not be described), the definition supplies the purpose, the behavioral caveat, and the per-check parameter routing. Nothing essential for correct invocation is missing.

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 the baseline is 3. The description adds cross-parameter routing logic beyond the schema: it clarifies that rank accepts either trackerId or siteId while site_audit requires siteId, a relationship the per-field schema descriptions only imply.

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 ('Sets how often a rank check or site audit runs') and enumerates the possible cadence values. Crucially it separates itself from the run_* siblings with 'Saving a cadence never starts a check', so an agent can distinguish scheduling from triggering 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 concrete routing: pass trackerId from get_rankings or siteId for rank, siteId for site_audit, and names run_rank_check/run_site_audit as related tools. It stops short of an explicit 'use run_rank_check when you want to trigger a check now' exclusion, so it is clear context rather than full when/when-not guidance.

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