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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds only the notion that results are join/link records; it says nothing about pagination behavior or result volume beyond what the schema already explains.

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 short sentences, resource first and filters second, with zero filler. Everything present earns its place and nothing could be trimmed without losing 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?

Adequate for a read-only list tool whose annotations and schema carry most of the burden, but 'site links' is left undefined (what fields a link record contains) and no output schema exists to compensate. Slightly more on the returned structure would make it complete.

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 page, per_page, site_id and service_area_id are already documented, including the automatic all-pages retrieval. The description restates the two filter params by name without adding semantics beyond the schema.

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?

Specific verb (List) plus a precise resource (site links for service areas), which distinguishes it from list_service_areas and list_sites. It never explicitly names those siblings, so an agent must infer the distinction from the resource noun alone.

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?

'Filter by service_area_id or site_id' tells the agent how to narrow results but not when to prefer this tool over list_sites, list_service_areas, or list_service_area_system_classes. No when-not guidance or prerequisites are given.

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