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

Annotations already signal this is not read-only and not idempotent, so the 'Add' wording adds little new safety information. The description contributes the prerequisite about an active Privacy & Cookie Policy, but it does not disclose failure behavior, duplicate handling, or side effects beyond creation.

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 tightly written sentences with no wasted words. The main action is front-loaded and the supporting lookup advice plus prerequisite follow naturally.

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?

The description covers the essential call path: which resource to add, how to find service IDs, and a key prerequisite. It is adequate for a straightforward create call, but it omits any indication of the response/return value or what happens if the Privacy & Cookie Policy requirement is not met, leaving some situational ambiguity.

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 descriptions cover all four parameters, so the baseline is 3. The description adds extra value by telling the agent where service_id comes from ('Use list_pcp_services') and implying site_id identifies the target site, which goes 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?

The description uses a specific verb ('Add') with a specific resource ('PCP catalog service') and target ('site'), making the action clear. It does not explicitly contrast with update_site_pcp_service or delete_site_pcp_service, but the add semantics and title are enough to distinguish it from most siblings.

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?

It gives a concrete prerequisite ('active Privacy & Cookie Policy') and a direct instruction to use list_pcp_services for finding valid service IDs. It does not spell out when to use update_site_pcp_service instead, but the context for this create operation is clear.

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