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

Annotations already declare readOnlyHint=true, so safety is covered structurally. The description adds that results are paginated and ties the call to a concrete REST endpoint, which is useful orientation, but it does not state result-size behavior or what a client record looks like.

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?

Three short fragments, front-loaded with the core action and filters before the endpoint detail. Nothing is redundant, though the telegraphic 'Paginated.' fragment is slightly clipped rather than elegantly brief.

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 full schema coverage and a readOnly annotation, the essentials are present. However, with no output schema, the description gives no hint about the shape or volume of returned client objects, leaving an agent to infer the return surface entirely.

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 page, per_page, is_active, and updated_since are all documented in the schema itself. The description only restates two of the four filters and adds no syntax (e.g., ISO-8601 form) beyond the schema, so the baseline of 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 verb and resource ('List clients') plus the filters it supports, and echoes the underlying endpoint (GET /clients). It is clearly distinguishable from harvest_get_client by the list-vs-single distinction, though it never names that sibling 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?

The mention of optional active-status and updated-since filters implies the use cases (syncing recently changed records, separating archived from active clients), but there is no explicit 'use this instead of X when Y' guidance against harvest_get_client or the other list_* siblings.

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