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

Annotations already declare read-only, non-open-world behavior; the description adds genuinely new behavioral context by disclosing that generation happens client-side via crypto.getRandomValues (the secret never leaves the device) and that the response includes an entropy figure. Minor tension worth noting: the emphasis on randomness sits awkwardly with idempotentHint=true, since repeated calls yield different passwords.

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 compact sentences, front-loaded with purpose and range, followed by the generation method. The trailing web-page URL is mildly promotional but short and harmless; nothing else is wasted.

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 6-parameter, all-optional tool with full schema coverage and no output schema, the description covers purpose, parameter bounds, generation environment, and hints at the returned payload ('entropy in bits'). The exact return shape (string vs. object with entropy) is not spelled out, which is the only real gap.

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% – every parameter (lower, upper, digits, symbols, similar, length) is documented in the schema with enums and a default. The description only restates the length bounds and character categories already present, adding no syntax or interaction detail (e.g. behavior when all character classes are set to 'no'). Baseline 3 applies.

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 and resource ('Make a random ... password') plus scope (8–64 characters, letters/digits/symbols) and a secondary output (entropy in bits). An agent can distinguish it from generic siblings like random_number_generator or word_counter, though the description never names an alternative explicitly.

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?

Usage is only implied by the tool's obvious domain: generate a password. There is no statement of when to prefer this over e.g. random_number_generator, no prerequisites, and no exclusions. Adequate but leaves the agent to infer intent from the name.

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