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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so the safety profile is covered. The description adds only the negative scope statement (no IP lookup); it says nothing about rate-limit or auth implications of the call itself, nor how limits are expressed.

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 short sentences, action front-loaded, zero filler. The disambiguating clause follows the core purpose rather than burying it.

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 no-argument read tool with no output schema, the description says what comes back (request and lookup limits plus current usage), which is enough to call it correctly. Return shape details are the only missing piece, and no output schema exists to cover them.

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?

Zero parameters, so the baseline is 4. There is nothing parameter-related the description could or should explain, and it correctly implies the call is argument-free.

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: 'Read account request and lookup limits and current usage.' The added sentence 'Does not look up an IP address' separates it from the two lookup siblings, though it never names them.

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 — an agent can infer this is the pre-flight/quota check before doing lookups, but there is no explicit 'use this when...' framing or reference to ipdetective_lookup_ip / ipdetective_lookup_batch by name.

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