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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds the composition contract that matters here: the tool produces a string payload that must be forwarded to generate_qr_code, and that the payload encodes a network phones can join. It does not mention escaping of semicolons/colons in SSIDs or passwords, a real behavioral caveat for this format.

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, zero waste: the payload shape and purpose come first, the downstream usage second. Every clause earns its place and nothing is repeated from the schema.

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 still tells the agent what the return value is (a WIFI: payload string) and what to do with it, and the four parameters are fully covered in-schema. Only the special-character escaping caveat for this encoding is unaddressed, which is minor for a pure builder tool.

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 every parameter is documented in-schema with defaults, enum values and the hidden/open-network cases. The description's format example only implicitly maps ssid→S, password→P, security→T, which is marginal added meaning. Baseline 3 applies when the schema carries the parameter burden.

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 verb (build) and concrete resource (Wi-Fi network payload), and even shows the emitted WIFI: format with T/S/P tokens. That is enough for an agent to distinguish it from the other qr_payload_* siblings (email, geo, sms, vcard) without opening any 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 forward: "Pass the result as `data` to generate_qr_code." That is real when-to-use guidance tied to a named sibling. It stops short of stating when not to use it (e.g. choose qr_payload_email for e-mail payloads), so not a 5.

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