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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the read-only nature is covered. The description adds the scoping information that this is a site-added PCP service, but does not disclose return behavior, error cases, or other operational traits. This adds some value without going beyond annotations significantly.

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 concise sentences with no filler. The main retrieval purpose is front-loaded, and the pointer to list_site_pcp_services is a useful addition that earns its place.

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 operation backed by readOnly/destructive annotations and a fully described schema, the description gives the agent everything needed: what to retrieve, how to identify it, and where to go for update/delete keys. No output schema exists, but none is necessary for this straightforward getter.

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 baseline is 3. The description clarifies that 'id' is the catalog service_id and that the resource is site-scoped, but it does not meaningfully enrich parameter understanding beyond what the schema already provides. The 'lang' parameter remains unexplained, though it is optional.

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 states a specific verb ('Get'), a clear resource ('PCP service added to a site'), and the lookup key ('catalog service_id'). It also distinguishes this from global catalog tools like get_pcp_service by emphasizing the site association.

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?

The description clearly implies this tool is for retrieving a site-specific PCP service by catalog service_id, and it points to list_site_pcp_services for finding primary keys. It does not explicitly name alternative get tools or exclusion conditions, but the context is clear enough for an agent to select it appropriately.

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