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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds useful payload context ('with its text in every site language'), but says nothing about error behavior for an invalid id or missing site.

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 with zero waste, and the core purpose is front-loaded ahead of the id-provenance hint.

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 simple read-by-id tool with full schema coverage and annotations covering safety, the description covers purpose, payload shape, and id provenance. Only minor gaps remain (no note on what happens with an invalid or cross-site id).

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% — both site_id and id are documented, including 'ID of the custom service (from list/create)'. The description's note about the id source repeats what the schema already says, adding no format or constraint details beyond it.

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 fully custom service of a site') and adds that the text is returned in every site language. It implicitly distinguishes itself from get_site_pcp_service via 'fully custom', but never names that sibling, so the differentiation is left partly to inference.

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?

Explicitly tells the agent where the required id comes from ('the id returned by list_site_pcp_custom_services or create_site_pcp_custom_service'), which is clear usage context. It gives no exclusions or guidance on when to prefer get_site_pcp_service instead.

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