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

The annotations already declare this a safe, idempotent, closed-world read. Beyond that, the description discloses two useful traits: the response bundles recent visits/notes rather than returning a bare client record, and cross-agency requests fail rather than leaking or returning empty. It does not say how much 'recent' data is included.

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, with the core purpose stated first and the failure condition appended. Nothing is redundant with the title.

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 read-only two-parameter lookup with no output schema, the definition covers scope, bundled data, and the authorization failure mode. The remaining gap is the semantics of 'recent' (window or count), which affects how the returned visits/notes should be interpreted.

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?

At 50% schema coverage, the schema documents clientId's origin ('Agency loved-one id from list_clients') but leaves agencyId bare. The description only indirectly touches agencyId through 'owned by this agency' and the cross-agency rejection rule, so the compensation for the undocumented parameter is partial.

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 uses a specific verb and resource ('Returns one client') and states the payload includes recent visits/notes. The singular 'one client ... owned by this agency' implicitly separates it from the sibling list_clients, but it never names that alternative outright.

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?

Usage is only implied: fetch a single known client, presumably after list_clients supplied the id. The 'rejected if the client belongs to another agency' line hints at the eligibility precondition, but there is no explicit when-to-use or when-to-prefer-alternatives guidance.

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