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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuinely non-obvious behavior — download links expire after 24 hours and are scoped to the signed-in practitioner, and the Client's note is attributed to the Client — which is real value beyond the annotations. It stops short of covering result ordering or volume limits.

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 sentences, front-loaded with what is returned, then the usage trigger. Dense but every clause carries information (returned fields, link lifetime, aggregation scope, note attribution). The opening sentence is long and stacks several facts, but none are filler.

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 compensates by naming the returned fields and the link expiry. For a two-parameter, zero-required read tool with full annotation coverage, an agent has everything needed to decide and invoke correctly.

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 the baseline is 3, but the description earns more by explaining the omission semantics: supplying no client means every Client in the Quarter, and the quarter scope defines the window. That meaning is only implicit in the schema, where both parameters are optional with no statement of what omitting client does.

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 opens with a specific verb and resource — 'Lists the files (name, size, received) a Client sent through their link for a Quarter' — and even previews the returned fields. It is clearly distinct from list_clients or get_client_history in substance, though it never names an alternative to steer the agent 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?

'Use this when: asked what a Client sent or to download it' gives a concrete triggering condition, and the 'or for every Client in a Quarter' clause hints at the aggregate case. There is no explicit when-not guidance or named alternative tool, keeping it below a 5.

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