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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior, so the safety profile is covered. The description adds useful substance beyond that by stating what the response contains (a verdict plus the missing LTE/NR bands per network), which is valuable given there is no output schema.

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 verdict/output shape front-loaded before the routing advice. No 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?

For a two-param read-only lookup with no output schema, the description covers the return content (verdict + missing bands) and the alternative paths adequately. It is nearly complete, with only minor gaps such as result granularity per network.

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%, so the schema already documents both parameters with examples (mf833v, Quectel EG25-G) and the ISO code / country name format. The description adds only the implicit hint that 'device' must be a known id (pointing to list_coverage), which is marginal beyond what the schema provides.

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 precise verb and resource: a verdict (good/limited/no) for a known module or device across every network in a country, including the LTE/NR bands it lacks. The scope and output shape are clear enough to distinguish it from siblings like check_bands and list_coverage without opening a schema.

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?

Explicitly routes the agent: use list_coverage to find device ids, or check_bands for a device that is not listed. This is exactly the when-to-use/alternative guidance that prevents mis-selection among the sibling tools.

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