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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds useful behavior beyond annotations: the output is 'ready-to-paste', includes reasoning and the crawlers it names, and omitting the argument returns all stances. There is no contradiction with annotations.

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?

The description front-loads a long JSON-RPC snippet for whoami before the actual purpose statement, making it noisy and poorly structured. The core explanation is economical, but the unrelated prefix wastes characters and could mislead an agent scanning the description.

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 single-optional-parameter read-only tool, the description covers the prerequisite call, what the tool returns, the no-argument behavior, and an example; the schema fills in the exact stance values. The main gap is not explaining why the whoami call is needed, but this is minor given the tool's simplicity and annotation coverage.

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% and the stance property lists all allowed values, so the schema carries most parameter meaning. The description adds the optional no-arg behavior and an example, reinforcing semantics beyond the schema. This earns a small bonus over the baseline 3.

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 clearly states the tool produces 'a ready-to-paste robots.txt block for one stance' with reasoning and named crawlers, so the verb and resource are specific. The opening JSON-RPC snippet for whoami is confusing but does not obscure the core purpose. It does not explicitly distinguish from siblings, but the task is distinct enough from the crawler-lookup tools nearby.

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 description gives a concrete prerequisite by instructing a 'FIRST CALL' to whoami with no arguments, and explains the omit-argument behavior to get all eight stances. It also provides a concrete example stance. It lacks explicit when-to-use vs alternative tools, but for a simple generator the guidance is adequate.

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