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

Annotations already declare readOnly, idempotent, and closed-world behavior, so the description only needs to add context — and it does: a 90-day data window, no live probing, no per-engine breakdown, no private audit data, and the missing-domain semantics. Return shape is never described.

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?

Three short sentences, front-loaded with the core action, then the exclusions, then the edge-case caveat. 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?

There is no output schema, so the description carries return-value burden and only describes what is not returned; what a result actually contains (scores, rankings, counts) is left unspecified. It is otherwise adequate for a three-parameter read-only lookup.

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 33%; only 'domain' is documented ('Website domain or URL'), while metro and service are bare enums. The description adds that metro and service are optional narrowing filters, which is useful, but it doesn't explain how the two enums interact or what combining them means.

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 ('Look up a domain in the public 90-day local index') plus the scope of the optional narrowing. An agent can distinguish it from a live-probe or audit tool, though the listed siblings (get_local_factsheet, get_local_market) are never named as alternatives.

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?

Clear context for when this applies: querying the recorded public index, not live probes, engine breakdowns, or private audit data. It also warns that a missing domain is not a zero score, which prevents a common misread. No explicit 'use X instead when...' routing.

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