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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety needs no restating. The description earns credit by disclosing what data actually comes back (field counts, frequent questions, reply latency), which matters because there is no output schema. It stops short of stating sourcing, freshness, or handling when an ATS has no data.

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 front-loaded sentence with no filler; the subject (facts about an application system) comes first and the return content follows. The trailing default-behavior clause is slightly tacked-on but earns its place.

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 one-optional-parameter, read-only lookup with no output schema, the description covers purpose, return contents, and the no-argument default. Only minor gaps remain: nothing about what happens for an ATS with no data, or the grain/recency of the statistics.

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 coverage is 100% with an enum, so the schema already defines the legal values, giving a baseline of 3. The description does add one piece of meaning beyond the schema: that omitting the parameter yields overall aggregate figures rather than an error, which is a genuine semantic contribution.

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 resource (facts about an application system/ATS) and enumerates the concrete contents: form field counts, most-asked questions, and employer reply speed. It is clearly separable from employer_facts and the job tools, though it never names those siblings to sharpen 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?

The clause 'Without a system, the overall figures' implicitly tells the agent to call it bare for aggregate stats and with a system for per-ATS detail. There is no explicit when-to-use vs when-not, and no mention of when employer_facts would be the better call.

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