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

readOnlyHint=true already tells the agent this is a safe, non-mutating read. The description adds only the trivial GraphQL mapping ('clients') and no behavioral traits such as pagination limits, result caps, or ordering, so it adds little beyond the structured fields.

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?

One tightly written sentence that front-loads the primary action (list) and then enumerates the alternative lookup modes. No filler, no redundancy.

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 zero-required-parameter list tool with a fully documented schema and a readOnly annotation, the description is nearly sufficient. Since there is no output schema, it could say a bit more about what a page of results contains, but the pagination contract is already in the parameter docs.

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 all five parameters (after, first, query, emails, client_ids) are already documented in detail. The description's inline example ('name = 'Jane Doe'', mobilePhone = ...) is a lighter restatement of what the schema's query description already covers, so the baseline 3 is right.

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 ('List the business's clients') plus the three search modes (email, id list, query). An agent can distinguish this from the singular boulevard_get_client by the plural 'list/search' framing, though the sibling is never named explicitly.

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?

Gives clear conditions for each mode: list everything, or filter by emails, client_ids, or a filter expression. It does not explicitly say when to prefer this over boulevard_get_client or boulevard_list_appointments, but the retrieval context is well implied for a read-only list tool.

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