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

Annotations already establish the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description's job is additive. It does add value: the visibility scoping ('sites you can see') and, importantly given there is no output schema, the shape of the return (status and live URL). It does not discuss pagination behaviour despite a limit cap of 50.

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, no filler. The purpose and scope come first and the chaining instruction second, which is the correct front-loading order for an agent scanning for a list tool.

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 two-optional-parameter list tool with no output schema, the description covers scope, returned fields and downstream usage, which is enough to call it correctly. The only gap is pagination/limit behaviour, which is partially mitigated by the schema's own limit documentation.

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 limit (default 20, max 50) and search (name substring) are fully documented in the schema. The description adds no further parameter semantics such as sort order or case-sensitivity of search, so the baseline 3 applies.

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 action (listing sites) with an explicit scope qualifier ('you can see in your organisation') and names the return content (status and live URL). It also distinguishes itself from get_site, edit_site and create_site by positioning itself as the source of ids those tools consume.

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 second sentence gives concrete routing guidance: take an id from here and pass it to get_site, edit_site or create_site. That is a clear, actionable workflow hook. It stops short of the 5 bar because it never states when NOT to use this tool (e.g. when to prefer search-based or filtered listing).

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