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

The readOnlyHint=true annotation already tells the agent this is a safe, non-mutating read, so the description does not need to restate safety. It adds only modest behavioral context (that the result is an aggregate count view with a 'most offline' ranking), and says nothing about whether counts are live or cached, or how the limit interacts with the ranking.

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?

A single compact sentence that front-loads the reported facts with no filler. It is efficient, though as a fragment it lacks the connective framing that would make the ordering of returned information explicit.

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 must carry the return-shape burden, and it only partially does: it names count metrics and a ranking, but leaves ambiguous whether the response is a single summary object or a list of client rows, and how 'limit' shapes that output. It is adequate for a simple read tool but not complete.

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 both parameters are already documented in the schema (limit default/max, client name or initials). The description adds no syntax or semantics beyond implying that results are grouped by client, which is the correct baseline of 3 when the schema does the heavy lifting.

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 states precisely what the tool reports: device counts, online/offline split, and the clients with the most offline devices. This is a clear content-level purpose, but it never distinguishes itself from the closely named sibling client_overview, so an agent must infer the boundary.

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 when-to-use or when-not-to-use guidance in the description. Nothing points to client_overview for per-client detail or explains how the optional client filter changes the use case; the schema's 'Leave it out for the whole company' is the only routing hint and it lives in a structured field, not the description.

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