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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds some genuine context beyond that: the exact fields returned and the free-plan client cap. It does not disclose pagination behavior or whether archived clients appear in the default result, so it is a modest addition rather than a rich one.

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 tight sentences with the core purpose front-loaded and no redundant filler. The plan-limit sentence is slightly tangential to listing but earns its place as an operational constraint.

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?

With no output schema, the description carries the burden of describing the return payload, and it does so by naming the fields returned (contact details, currency, hourly rate in cents, per-client project count). Combined with annotations that cover safety, this is nearly complete; only pagination and archived-inclusion behavior are left implicit.

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% (the single includeArchived param is documented with its default), so the schema does the heavy lifting and the baseline is 3. The description does not mention archiving at all, adding no semantics beyond the structured field.

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 gives a specific verb and resource ('Lists the user's clients') and even clarifies the domain concept ('the companies or people projects are done for'), so the agent knows exactly what entity is returned. It enumerates the returned fields (contact details, currency, hourly rate in cents, project count), which further pins down the purpose. It does not explicitly distinguish itself from sibling reads like get_client_portal or create_client/archive_client, but the listing verb makes the role obvious.

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?

There is no explicit statement of when to use this tool versus alternatives such as get_client_portal, list_projects, or search. The 'free plan includes 2 active clients' note is a quota fact, not routing guidance. Usage is only implied by the tool name and purpose.

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